An objective forecast of the snowmelt hydrograph - McCallister, J.P.; Johnson, R. (30th Annual Western Snow Conference, 1962)
An outline of a simple objective method, applicable in the Great Plains area, is presented for forecasting streamflow from both snowmelt and precipitation. Current temperature, precipitation and snow depth data are used in the forecast procedure which is fashioned after the Unit Hydrograph procedure. The basin or area runoff is then computed from appropriate rainfall-runoff relationships.In discussion Donald L. Miller points out some differences in opinion as to the degree-day interpretations to temperature values for snowmelt computations for the Great Plains area.
Keywords: Unit hydrograph, Water supply forecasting

Aerial snow depth marker configuration and installation considerations - Miller, R.W. (30th Annual Western Snow Conference, 1962)
A detailed description of aerial snow depth marker poles with cross-bars at 2 foot intervals, is shown in construction drawings and pictures. Site selection specifications are included in the text.
Keywords: Aerial markers, Equipment, Snow surveys

Discussion of paper "An objective forecast of the snowmelt hydrograph in the plains region" - Miller, Donald L. (30th Annual Western Snow Conference, 1962)

Snow in the trees -- where does it go? - Miller, D.H. (30th Annual Western Snow Conference, 1962)
A neglected aspect of hydrology is the snow caught in the forest canopy. Meteorological conditions existing during and after a snow storm are not conducive to evaporation. visual observations and interpretations are available but few instrumental measurements have been made. Mechanical action is short-lived and effectiveness of snowfall has been studied.In discussion Mr. M.D. Magnuson indicates that the shape of the type of snowflake could very well effect the clogging procedure of snow in the forest trees and that evaporation factors are at a low value after a snow storm.
Keywords: Interception, Snow evaporation

Economic consideration of water yield forecasting for the Salt River Valley, Arizona - Moore, R.E. (30th Annual Western Snow Conference, 1962)
Snowmelt water provides the major portion of the annual runoff to the Salt River Project System. The worth of this runoff, equated to the basic snow survey data and resulting water yield forecast, is discussed in terms of some economic considerations. These considerations are emphasized from the standpoint of the application by a water user of such forecast information.In discussion Mr. Jesse D. Ellis describes his application of Mr. Moore's economic theories to the savings possible in power development by having advance knowledge of a possible 10 percent plus or minus average potential runoff into reservoirs by forecasting.
Keywords: Economics, Water supply forecasting

Snowpack evaporation - Peak, G.W. (30th Annual Western Snow Conference, 1962)
Varying winter wind velocities provide an evaporation index of Wyoming's wind-swept mountain snowpack. Wind movement at the 700 millibar level was obtained from up-wind Weather Bureau stations and is used as an added independent variable together with April 1 snow survey data, soil moisture and June precipitation, to develop a streamflow forecasting procedure. A series of 16 graphs illustrate the procedure.In discussion Mr. R.M. Sensintaffar points out the successful use of this wind evaporation index in forecasting the inflow to Pathfinder Reservoir on the North Platte River, Wyoming. Five tables show the array of data and also evaporation data for the reservoir surface.
Keywords: Evaporation, Sublimation, Water supply forecasting, Wind movement

Snow surveys in West Pakistan water resources development - Priest, J.E. (30th Annual Western Snow Conference, 1962)
An illustrated discussion of a newly established network of snow survey courses to be used in forecasting streamflow of the Kunhar River. The gigantic Indus Basin Settlement Project is designed to create a system of reservoirs to impound over 50 million acre feet of water for power development and irrigation of some 25 million acres of land in West Pakistan. A system of water transportation between the Jhelum, Chenab, Beas, Sutlej, Ravi, Indus and Kunhar Rivers is planned through a complex of canals.
Keywords: Networks, Pakistan

Diurnal fluctuation of free-water content in a melting snowpack - Rantz, N.E. (30th Annual Western Snow Conference, 1962)
Diurnal fluctuation of free-water and density occurs during the day melting period when the rate of snow melt is high and exceeds the capillary capacity of the snowpack. At night when the rate of the melting becomes insignificant, the excess free-water drains from the pack. Snow samples were taken horizontally at one foot intervals of depth and at four hour intervals from the face of a pit dug 65 inches to soil surface. Samples were weighted for water equivalent and calorimeter procedures were used to determine free-water content. Vertical samples were also taken to determine the average density and water content of the pack for comparison.
Keywords: Density, Snow research

TIROS IV weather satellite - Tarble, R.D. (30th Annual Western Snow Conference, 1962)
Pictures taken by weather satellite are exhibited to show the extent of snow cover over the western mountains on April 11, 1962. The possibility of using satellite pictures for measuring the area of snow cover in river basins during the melt period is intimated.
Keywords: Aerial mapping, Snow cover, TIROS, Weather satellite

Application of aerial snow cover observations to forecasting Flathead Lake inflows - Thoms, M.E. (30th Annual Western Snow Conference, 1962)
A procedure is developed to forecast the potential inflow to Flathead Lake, on the Columbia River system in Montana by using the area covered by snow obtained by aerial flight and mapping during flight over the basin. The procedure is primarily for short term forecasting after May first. This information is used in reservoir regulation and management. The snow cover data is used in connection with temperature and current precipitation values. Reconstituted hydrographs are shown in comparison with observed hydrographs.
Keywords: Short term forecasting, Snow cover distribution, Water supply forecasting

Snowpack ratios in runoff forecasting - Work, R.A.; Beaumont, R.T.; Davis, R.T. (30th Annual Western Snow Conference, 1962)
A new approach to streamflow forecasting is presented by taking into consideration the differences in characteristics of the winter's snowpack in the particular basin. Instead of using one formula for all years, the new scheme takes into consideration the relation of the high elevation snow in respect to the low elevation snow water content on a ratio basis. A formula based on average or best fit conditions may not be best for a particular year. The procedure differentiates on an objective criteria so as to use formula developed from years to fit the specific characteristics of the winter at hand. Several formulas may be needed to meet the conditions of a single basin.
Keywords: Water supply forecasting

Fuctuations of effective annual precipitation - Yevdjevich, V.M. (30th Annual Western Snow Conference, 1962)
A mathematical study is presented involving the fluctuation in effective precipitation and resulting effects on streamflow for the water year. Effective precipitation is defined as the total precipitation minus evapotranspiration for the water year. This investigation is made by random time series as a yardstick to the effective precipitation and streamflow. The statistical technique is exclusively the series correlation process, through the analysis of range and runs. The results of the study indicate a possibility of predicting future long-range water yields from the time series computations.
Keywords: Effective precipitation, Statistical analysis, Time series

1961 Title, Contents, and Minutes (29th Annual Western Snow Conference, 1961)

Heat balance at the surface of the Artic Ocean - Badgley, F.I. (29th Annual Western Snow Conference, 1961)
A resume of available data on the components of the heat budget of the Arctic Ocean surface shows that radiative interchange with environment is the dominant factor. The presence or absence of an ice cover influences the nature of this interchange and also the relative importance of evaporation to the budget. On the basis of these figures a conjecture is made as to the cause of events in the artificial removal of the ice cover. It is shown that the ice would re-establish itself under presently existing conditions.In discussion Mr. Clarence Pederson points out the advantages of measuring the heat balance in the Arctic Ocean, and mentions possibilities of using the theory and instrumentation for snow melt problems in reservoir control of downstream water temperatures.
Keywords: Artic Ocean, Heat balance, Ice

Forecasting he date of low flow (2000 cfs.) on the East Carson River, Nevada - Barton, M. (29th Annual Western Snow Conference, 1961)
A forecast procedure of critical low flow using two parts is presented. The first part for early season forecasting (March 1, April 1, and May 1) uses snow survey data only. The second phase utilizes the peak flow height and date of occurrence as coded days after April first. This information is reported to users as a weekly span such as 'the last week of July' or 'the second week of august'. A location map is exhibited and an array of data is shown in tables with statistical parameters.
Keywords: Critical flows, Water rights, Water supply forecasting

Maximum snow depths and snow loads on roofs in Canada - Boyd, D.W. (29th Annual Western Snow Conference, 1961)
Tabulations were made of annual maximum depths of snow on the ground at 200 stations in Canada for the period 1941-59. An extreme value distribution was fitted to the observed maximum and then used to obtain the maximum snow depth for the 30 year period. These data were plotted and zones created to show maximum snow depths. Snow loading for buildings were computed for the zones including data form precipitation data on top of snow. The maximum snow load on roofs has been established tentatively as 80% of the maximum snow load on the ground.A formal discussion is presented by Marvin D. Magnuson, who exhibits mathematical and graphical procedures for solving extreme probability of meteorological factors to assist in extending values such as snow load data. Three references are listed.
Keywords: Snow cover accumulation, Snow loads

Needs for special water supply forecasts to meet unusual water rights and irrigation requirements for the Sevier River Basin in Utah - Callister, L.C. (29th Annual Western Snow Conference, 1961)
A description of the Sevier River system with reservoirs and locations of gaging stations is presented. A resume of water rights by Court Devree is included with details of a division into primary and secondary categories of rights with the water volumes proportioned by percentages. Winter storage as well as spring storage is apportioned by water rights. Return flow plays an important part in the operation of this desert river basin. Accurate volume flow forecasts are made from snow survey and precipitation gage measurements. Low-flow forecasts aare very important in water apportionment.
Keywords: Critical flows, Water rights, Water supply forecasting

Low-flow forecasts on the Rogue River - Frost, W.T. (29th Annual Western Snow Conference, 1961)
A critical low-flow forecast of the Rogue River is developed to meet demands of irrigation district management for information as to dates they could expect the river flow to drop below 900 cfs., when pumping operations must commence to satisfy water user demands. By using the date and height of peak flow the falling limb of the hydrograph is easily constructed to the 2000 cfs., and the coded number of days to reach 900 cfs., after March 20. Three graphs are exhibited to show the relation between variables used and the array of data is shown in tables with statistical parameters.
Keywords: Critical flows, Water rights, Water supply forecasting

The simulation of a blowing snow environment in a wind tunnel - Gerdel, R.W. (29th Annual Western Snow Conference, 1961)
A resume of research studies dealing with drifting snow is presented with emphasis on the techniques of model design with materials scaled down to simulate blowing snow for wind tunnel studies. Commercial borax was found to fit closely the design specifications. Wind velocities up to 100 knots were used. Drifting patterns were studied and compared with similar life sized structures now being used in the snow covered wind blown areas of the Greenland Ice Cap.
Keywords: Simulation, Snow drifting, Snow storm, Wind tunnel

Snowfall and snowfall accumulation near Climas, Colorado - Grant, L.O.; Schleusener, R.A. (29th Annual Western Snow Conference, 1961)
An investigation of snowfall over the higher elevations of the Rocky Mountains, in Colorado is being carried on by Colorado state University. This investigation is described and preliminary findings are discussed. The current field program includes daily snow observations of new snow at 65 sites space at about one mile intervals over Fremont, Hoosier and Vail Passes. In addition, certain atmospheric observations are being made, with seeding operations using Silver Iodide generators from upwind sites operating on randomly selected days. Specific observations are made relative to: efficiency of snowfall observing devices; characteristics of snowfall observation sites; snowfall variations with elevation, exposure; concentration of ice nuclei and their relation to snowfall. This study is continuing with emphasis on atmospheric observations and seeding.In discussion Homer Stockwell points out some factors to be considered in the operation of the study and the analysis of data.
Keywords: Snow hydrology research, Weather modification

Benefits of forecasting date of low snow to water users of the Carson River - Johnson, W. (29th Annual Western Snow Conference, 1961)
Problems of the cattle rancher using water for irrigation from un-regulated streams where water rights regulations necessitate the shutting off of the use when critical flows are reached. These shut-off dates are critical to crop development and harvest, and play an important part in the economy of the operations. Also the date of probable shut-off of primary and secondary water rights can be forecast within reasonable degree of accuracy is a step towards great economy in farming the semi-arid west areas.
Keywords: Critical flows, Water rights, Water supply forecasting

Plains snowpack water equivalent from climatological records - McKay, G.A.; Blackwell, S.R. (29th Annual Western Snow Conference, 1961)
Climatological measurements of daily snow on the ground and precipitation gage values for a long period of record from the plains area of Alberta, Saskatchewan, and Manitoba, Canada were converted into usable data of snowmelt water yield. The lack of sufficiently long records of plains snow survey data necessitated the development of an energy budget conversion formula to make climatological records collected in the past usable for modern analysis work. Graphs, illustrations, and tables show the relationship of the parameters studied. A comparison of the Mount Rose snow sampling tube and the Prairie snow sampling tube are shown.
Keywords: Comparison, Prairie sampler, Snow sampler tube

A method of forecasting stream runoff for Snake River at Brownlee - Mitchell, W.B. (29th Annual Western Snow Conference, 1961)
A solution to relatively accurate forecasting of the April-June runoff period on the Snake River at downstream points below twenty reservoirs and twenty-five major irrigation diversions is presented. The calculated natural flow is first derived by correcting the observed flow for all reservoir storage and major irrigation diversions by using a multiple regression formula containing snow survey data and the previous years precipitation for August-October. A relation was developed between the observed flow and the calculated natural flow. The average error for this relation is close to 7.0% and the average error in attempting to estimate the reservoir operations is close to 16%. The array of data and results of forecast accuracy are shown in the four tables.
Keywords: Reservoir regulation, Water supply forecasting

Critical flow forecasting for irrigation requirements in the Sevier River Basin, Utah - Pearson, G.L.; Peck, E.L. (29th Annual Western Snow Conference, 1961)
A forecasting scheme is developed to satisfy the water rights problems existing along the Sevier River, Utah. When the river reaches its peak flow, the primary water rights are satisfied. As the streamflow gradually decreases the problem of satisfying the decreed water rights becomes more acute. The proposed forecasting will point out these deficiencies ahead of time so that rotation of irrigation demands can satisfy the demands. A percentage of the primary water rights are delivered so that all users receive their just portion of the available water. Because good records are available for most of the Sevier River, it has been possible to develop these forecasts within reasonable accuracy. In some cases, better diversion records and more streamflow records would have been helpful.
Keywords: Critical flows, Water rights, Water supply forecasting

Peace River project with specific reference to reservoir filling and runoff forecasts - Sampson, F. (29th Annual Western Snow Conference, 1961)
A description of the Peace River power development project is presented with emphasis placed on the importance of economical reservoir operation. It is stated that presently developed water supply forecast schemes have an accuracy of 15 percent and that this accuracy will show an economical saving of a million dollars worth of power a year. Volumes of river flow up to 22 million acre feet are involved.A discussion by Mr. T.A.J. Leach points out the establishment of five new snow survey courses within the Peace River catchment area to supplement the four existing courses now operating in the adjacent Fraser River basin which have sufficient length of record to be used in forecasting. Other climatological factors will also be measured and reported.
Keywords: Power development, Reservoir regulation, Water supply forecasting

Short range snowmelt forecasts - Schermerhorn, V.P. (29th Annual Western Snow Conference, 1961)
A procedure is described for preparing successive daily forecasts of streamflow from snow melt over the West Kootenay River Basin in British Columbia. The system is based on temperature index which varies proportionally with streamflow. An adjacent small basin is used as a contributing index area. A series of graphs are included to illustrate the procedure.A discussion by Mr. David M. Rockwood suggests that the inclusion of a percentage index of the area covered by snow from serial observations would add materially towards increasing the accuracy of forecasts along with the falling limb of the hydrograph. Two graphs are included for developing this factor.
Keywords: Day to day procedures, Runoff, Snowmelt, Water supply forecasting

Changes in snowmelt runoff caused by reforestation - Schneider, W.J. (29th Annual Western Snow Conference, 1961)
A study of runoff from a reforested drainage area in upper New York State where rehabilitated land was replanted to five species of conifers during a period of 25 years. A net decrease in total runoff is shown as well as a decrease in the size of the peak flow for most of the years of study. The reduction of peak discharges is attributed largely to the delayed melting of that portion of the snowpack which is not protected by forest cover, where 58% of the watershed had not been replanted.Mr. Nedavia Bethlahmy presents a complete discussion of the paper, and indicates that the runoff pattern of the test basin had changed with time as compared to the control basin, also that the magnitude of peak flow had changed as much as 41 percent on the average.
Keywords: Forest management, Runoff, Snowmelt

Effect upon irrigation of critical low-flow of the Rogue River - Shaffer, N.F. (29th Annual Western Snow Conference, 1961)
Problems presented to an irrigation district manager when a critically low flow of water is forecast for the stream from which his district's supply is derived are discussed in detail. Economical problems arise either to obtain additional supplies from pumping or conserving the existing supply by rotation of demands and sometimes a loss of certain crops. The necessity of obtaining an accurate forecast of flows to the district supply point prior to occurrence so that plans can be made in advance is brought out in the discussion.
Keywords: Critical flows, Water rights, Water supply forecasting

Glacier studies in British Columbia - Strilaeff, P.W. (29th Annual Western Snow Conference, 1961)
The Water Resources Branch, Canada Department of Northern Affairs and Natural Resources has made surveys of selected glaciers since 1945 to determine the effect of glacier variation on runoff. the glaciers selected for study were the Helm, Sentinel, and Sphinx, all of which are in Garibaldi Park, and the Kokanee and Illecillewaet Glaciers in the Selkirk Mountains. These glaciers were surveyed annually through 1950 and have been surveyed biennially since that time. In each case, reference points have been established and distances of the glacier forefoot from these points have been measured, or the forefoot has been mapped in relation to the markers. Camera stations have also been established. Since 1947, surface velocities have been measured by means of markers set in the ice. Changes of thickness have been measured by cross sections. Data on frontal variations for the period 1945-58 are tabulated, a summary of early observations is included.
Keywords: Glacier research

1960 Title, Contents, and Minutes (28th Annual Western Snow Conference, 1960)

Prospects for affecting the quantity and timing of water yield through snowpack management in California - Anderson, H.W. (28th Annual Western Snow Conference, 1960)
One of four papers dealing with snow hydrology of water yield from forested areas in different sections of the United States and different climatic and vegetative types.A resume of past studies performed in the several California forests is presented. The effects of logging operations and the various type of timber cutting patterns, strip, block, clear, and selective cutting practices are studied to determine the water yield from each area so affected. Logging slash disposal methods are also studied with their effects upon water yield and also reforestation and effects on soil moisture. Various aspects and slopes of forested areas were considered.
Keywords: Forest management, Snowpack water yield

Use of snow survey reports in predicting snow runoff - Ball, H. (28th Annual Western Snow Conference, 1960)
A discussion of meteorological occurrences of flood and drought over the Rio Grande river basin is presented. It is pointed out that for the lack of sufficient data to prove any long time or even short cyclic occurrences of weather pattern, the prediction lacks a solid mathematical basis. Historical data from archaeological findings are quoted. The beneficial use of short term (15 year) averages of snow survey, temperature, wind movement, and soil moisture data produce a good forecast of streamflow during the melt season. The economical value of advance information for regulating irrigation reservoirs is pointed out as a distinct value to both power and irrigation interests.
Keywords: Reservoit regulation, Water supply forecasting

New instruments of the surface water branch, United States Geological Survey - Barron, E.G. (28th Annual Western Snow Conference, 1960)
A detailed description of recently developed hydrographic equipment for measuring streamflow, is presented. Each of the following pieces of equipment are described and how the equipment is used to aid accuracy and economics of water measuring procedure. The electromagnetic velocity meter; the acoustical velocity meter; the bubble stream gage; the stream surface follower and recorder. The sonic flood measuring assembly and the digital recorder are depicted in photographs and diagrams. The theory of operation and performance of recorders are discussed. Plans are made for field testing these pieces of equipment and to re-design present concepts.
Keywords: Hydrology stream measurements, Water measurement

Application of the electronic computer to seasonal streamflow forecasting - Codd, A.R.; Farnes, P.E. (28th Annual Western Snow Conference, 1960)
A discussion pertaining to the use of the electronic computer for developing multiple regression formulas to be used in water supply forecasting for the rivers of Montana. The economics of using the electronic computers, to save man-hours, increase accuracy and have available a better selection of independent variables for use in the formula is brought out. Cost figures of manually operated calculators and the electronic computer handling the same, problem are shown.Discussion by Robert T. Davis indicates a confirmation of the economic value of using electronic computers for developing forecasting formulas. A step-by-step program for the computer is described and its benefits shown.
Keywords: Electronic computer, Snow cover, Statistics, Water supply forecasting

Reservoir evaporation and its reduction - Gartska, W.U. (28th Annual Western Snow Conference, 1960)
A detailed technical discussion of reservoir evaporation is presented with several criteria for reducing evaporation. A description of how monomolecular layers of several different materials reduce evaporation is presented, including the action of cetyl alcohol or hexadecanol. A description of the experimental work in this field is also presented, including the details experiment, and safeguards set up by the steering committee, that included, State and Federal Health Departments, Geological Survey and Bureau of Reclamation representatives. Work on other reservoirs was also indicated where the toxic effect of the monomolecular layer material might affect fish, water fowl, or other plant or animal life. The durability of the layer on reservoirs was studied. A substantial list of references of reports and other experimental programs is included with the paper.
Keywords: Evaporation reduction, Reservoir evaporation

A proposal for incorporating aerial snow-depth markers into water supply forecasts - Hannaford, J.F. (28th Annual Western Snow Conference, 1960)
The advantages and disadvantages of using aerial observed snow depth markers as compared to ground snow survey data in water supply forecasting computations are described. The relative costs are discussed. A ten year study of forecasting the runoff of the Kings River by both methods is presented for comparison. Conclusions indicated that aerial observations are sufficiently accurate for early forecasts of January through March, while the ground snow surveys with actual water content measurements are far more accurate and necessary for a dependable April first forecast of the water supply expected from snowmelt.
Keywords: Aerial snow marker, Water supply forecasting

Prospects for affecting the quantity and timing of water yield through snowpack management in Southern Rocky Mountain area - Hoover, M.D. (28th Annual Western Snow Conference, 1960)
One of four papers dealing with snow hydrology of water yield from forested areas of different climatic areas in the United States.A discussion of water yield problems from the Rocky Mountain areas of Wyoming, Colorado, and New Mexico is presented in relation to the Alpine Zone and Sub-Alpine Zone. These zones are described and their definite effect on water yield. Various methods of timber cutting effects are discussed. Wind movement of snow are mentioned as a serious problem. Studies in the White Mountains of Arizona are included in the discussion.
Keywords: Forest management, Snowpack water yield

Use of the electronic computer for streamflow analysis - Johnson, L.F. (28th Annual Western Snow Conference, 1960)
A description of the processes used on the electronic computer for deriving multiple regression formulas using the many independent variables required in snow water supply forecasting is presented. The advantage of obtaining statistical relations between as many as 33 variables and streamflow figures within 15 minutes is shown. The detail results and procedures for developing a multiple regression formula for the Madison River at West Yellowstone, Montana with explanation of results, are given. Reasons for the 4 different forecast periods, together with peak flow and number of days to exceed critical flows are described. Four tables are included to show the results of the statistical criteria and formulas used.
Keywords: Electronic computer, Snow cover, Statistics, Water supply forecasting

Trafficability tests of over-snow vehicles - Lanyon, J.J. (28th Annual Western Snow Conference, 1960)
A report of extensive tests is presented dealing with drawbar pull; power efficiency; type of trackage; type of and number of grousers; type and spacing of bogie wheels. Highly efficient electronic sensing devices and recorders were used to collect the values of the various parameters above. A comparison of numerous factors involved are shown in graphs and tables with photographs of machines and various parts tested. Duplicate tests were performed on several makes, models, and sizes of vehicles.A discussion is presented by Mr. R.A. Work, who also presented results of field tests made by snow surveyors of the Soil Conservation Service who use a variety of machines.
Keywords: Over-snow vehicle tests, Transportation

Prospects in the Northeast for affecting the quantity and timing of water yield through snowpack management - Lull, H.E.; Pierce, R.S. (28th Annual Western Snow Conference, 1960)
One of four papers dealing with snow hydrology of water yield from forested areas of different climatic areas in the United States.Water yield from the snowpack zone for the States of New York, Vermont, New Hampshire, and Maine are discussed with relation to forest type (hardwood or conifer). A map, graphs, and tables illustrate the wide scope of data analyzed. Flood protection through snowpack management is shown to be the primary problem in the North-east States.
Keywords: Forest management, Snowpack water yield

Use of snow-melt forecasting by the Corps of Engineers for flood control operations of the Rio Grande River - Martin, J.T. (28th Annual Western Snow Conference, 1960)
The Federal law under which the U.S. Corps of army Engineers is authorized to enter into the construction, operation and regulation of flood control structures such as dams, levees, and river channel improvements of future streamflow management, is outlined. The three operational divisions of the Rio Grande River above El Paso, Texas are delineated on a map and the plan of regulation is described. The absolute need for accurate water supply forecasts from snow survey data, precipitation and soil moisture data is shown. Case histories and operational techniques are described showing further need for reliable forecasts and the close cooperation of all agencies involved.
Keywords: Flood control prediction, Water supply forecasting

A look at avalanche control structures in Europe - Martinelli, M. Jr. (28th Annual Western Snow Conference, 1960)
A discussion of four types of avalanche control structures observed in Switzerland, Austria and France. The first type of structure is built in the avalanche path to hold the snow in place. The second type is a set of baffles to deposit blowing snow and secure it in place. The third type is a retaining structure in the lower portion of the slide path to act as a buffer to retain the slide. The fourth type of structure is a deflecting type to turn the slide sway from the ordinary path of the slide. The several structures are sketched and described on plates.
Keywords: Avalanche control

Automatic measurement of hydrologic paramaters at remote locations - Maxwell, L.M.; Warnick, C.C.; Beattie, L.A.; Hespelt, G.G. (28th Annual Western Snow Conference, 1960)
The purpose of a hydrologic telemetering system is to provide data on snowmelt runoff parameters from remote mountain locations at frequent intervals and at sites where such information is pertinent to operating reservoirs for flood control, irrigation, and power releases. The system is devised by the Engineering Experiment Station, University of Idaho at Moscow. The parameters selected for measurement are; total accumulation of precipitation, soil moisture, air temperature, snow quality (wetness), snow water equivalent, and the snow depth. A description and photos of the several procedures for measuring these parameters are shown, also schematic diagrams of the electronic telemetering systems at the sending and receiving end of the system.
Keywords: Telemetering systems

Some terrain and forest effects on maximum snow accumulation in a western white pine forest - Packer, P.E. (28th Annual Western Snow Conference, 1960)
One of four papers dealing with snow hydrology of water yield from forested areas of different climatic areas in the united States.An analysis of a four year study of the effects pertaining to snow accumulation. Size of year (above or below average), elevation aspect and percent canopy cover, all are shown to have a marked effect on the water yield from areas in the Northern Rocky mountain forest covered watersheds in the Priest River Experimental Forest, northwest of Spokane, Washington. A curvilinear multiple regression formula was used to evaluate the individual effects of the several independent variables on snow water accumulation.
Keywords: Forest management, Snowpack water yield

The avalanche defence on the Trans-Canada highway at Rogers Pass - Schaerer, P.A. (28th Annual Western Snow Conference, 1960)
A detailed description of plans for highway maintenance through avalanche areas across Rogers Pass, British Columbia. Approximately 120 avalanche paths in 24 miles of highway are classified into four categories according to frequency of avalanche occurrence. A description of preventive or control measures for each category are suggested. Avalanche forecasting and warning procedures are explained together with plans for artificial release of small slides to prevent a disastrous avalanche. Maps and photographs depict the scope of the project.A formal discussion of the paper is presented by W.M. Borland, who cites technical problems of avalanche control on highways leading over the Rocky Mountains of Colorado. Avalanche control by artificial release are discussed. Comparisons of Colorado conditions are made with those conditions found on Rogers Pass.
Keywords: Avalanche control

Precipitation trends in Arizona and western New Mexico - Sellers, W.D. (28th Annual Western Snow Conference, 1960)
A statistical study of precipitation data covering a 40-year period (1917-1957). Data from 18 selected stations representing the arid west of New Mexico and Arizona. The several graphs are used to show the combined results of statistical parameters to show precipitation trends throughout the period studied. A comparison of annual summer and winter periods are made to further the trend study.
Keywords: Precipitation analysis, Statistical analysis

1959 Title, Contents, and Minutes (27th Annual Western Snow Conference, 1959)

Logging effects on snow, soil moisture, and water loss - Anderson, H.W.; Gleason, C.H. (27th Annual Western Snow Conference, 1959)
The results of studies in California on the effects of various types of logging on the water yield from snow are reported. The studies were made on an 18.7 acre strip cutting 300 feet wide and 2500 feet long, on a 17.1 acre block cutting 800 feet wide and 1800 feet long, and on a commercial diameter limit cutting. The controls were natural openings and forest stands. All three methods of logging increased maximum snow accumulation and decreased annual water losses. At maximum depth the strip cutting showed 10 inches more water than the un-cut forest, block cutting and the commercial cutting showed 5 to 7 inches more. The rate of snow melting was greater in the commercial cutting areas than in the un-cut forest. Small amounts of snow remained longer in the un-cut forest. Summer soil moisture losses in soils 48 inches deep, were decreased by logging while the annual water yield from precipitation was increased.
Keywords: Logging effects, Runoff, Snowmelt, Soil moisture

History of snow surveying in the east - Ayer, G.R. (27th Annual Western Snow Conference, 1959)
A historical resume of snow surveying starting in 1914 in the Eastern States of the United States is presented, with references to snow observations recorded as early as 1899. A description of instrument development, tools and field procedures is presented. Water supply forecasting from snow survey measurements is described as handled in the early days of the science. Procedures are presented for distributing the data on a cooperative basis by several agencies and companies using the water supply forecasts. Although the data is not as widespread in the East, it is equally as important to the municipal water supply agencies and for use in supplying water to canals in the East.
Keywords: History, Snow surveys

The photocanopymeter - Codd, A.R. (27th Annual Western Snow Conference, 1959)
A photo process of measuring the density of the forest canopy cover over a fixed point in the forest is described. A pin-hole camera with film transport was constructed. The pin-hole was used to eliminate spherical distortion of the 'Fish-eye' lens ground for 90 deg wide angle photography. The 90 deg field of view was used to comply with Weather Bureau standards for precipitation gages, where it is required that the gage must be in the clear at 45 deg in all directions of obstructions. The camera is leveled and oriented N & S, pointed up and a time exposure of approximately 2 seconds is made over each snow sampling point on a snow survey course. A dot planimeter grid was developed for sandwiching with the negatives from the pin-hole camera shots. Dots covered by forest canopy are counted and proportioned to uncovered dots to obtain the percent forest canopy cover over each sampling point. Photographs of the camera, negative, grid and conversion tables are shown along with an illustration of the tabulation forms for data.
Keywords: Fkorest canopy cover, Fkorest cover measurement, Forest cover photography

Economics of early season snow surveys - Hannaford, J.F. (27th Annual Western Snow Conference, 1959)
Snow surveys made prior to the optimum date of April first are shown to be economical in value to water users, depending upon the use made of the early season forecast. although snow surveys are expensive to make in some cases, the accuracy of the forecasts prepared from these data as compared to alternative forecasts based on other data is outstanding and well worth the expenditure. Purely graphical methods are used and illustrated by using the flows of the Kings River inflow to Pine Flat Reservoir, California.
Keywords: Snow survey normals, Water supply forecasting

Snow management research in the Sierra Nevada, a review and a look ahead - Hopkins, W. (27th Annual Western Snow Conference, 1959)
A resume of snow research by Dr. J.E. Church Jr. is presented in a philosophical trend. Early concepts of Dr. Church relative to the conservation of snow for water supply as well as the conservation of forest products through better forest management, are discussed as related to a more stable water runoff period. The early concepts and needs of better water supply forecasting from snow surveys are forcibly brought to mind. This paper is a great tribute to Dr. Church, a humanitarian, a self-made scientist of snow water conservation.
Keywords: Forest management, Snow hydrology

Preliminary report on evaluating the utility of water supply forecasting - Kohler, M.A. (27th Annual Western Snow Conference, 1959)
A discussion and comparison of two basic theories of water supply forecasting, one based primarily on rainfall measurements and the other based primarily on snow survey water content measurements. The 1947-57 period of years is used for comparison. A close similarity of forecast accuracy of both methods is illustrated by graphs. The conclusion states that a combination of the two independent variables would produce a more accurate forecast. Reference is made to a similar paper presented in the 1958 snow conference, WSC Paper No. 328-58.
Keywords: Forecast accuracy, Water supply forecasting

Aerial reconnaissance of mountain snow fields for maintaining up-to-date forecasts of snow melt runoff during the melt season - Parsons, W.J.; Castle, G.H. (27th Annual Western Snow Conference, 1959)
A simple graphical method of determining the runoff volume to be expected after any date in the melt season by means of serial surveys of the snow line is described and evaluated on the basis of a 6-year study of the Kings and Kern River basins in California. Snow-line areas are sketched while in flight by using a transparent overlay on an aeronautical chart. Registration marks are placed on the overlay for use with subsequent flights. The areas are measured and the volumes computed. Water content of snow surveys are used to compute the volume of water remaining in the snowpack. This data is applied graphically to charts to determine the volume of water to be expected during the ensuing months of the runoff period. The resultant current forecasts had average errors of less than 10 percent during the critical period from 75-30 days before the end of the melt season.
Keywords: Photography snow line, Runoff, Snow cover distribution, Snowmelt

Snow melt curves - Richards, H.B. (27th Annual Western Snow Conference, 1959)
A snow melt water forecast procedure is developed using temperature, ground water, wind movement, precipitation and snow water content combined to plot against runoff. This graph is called a snowmelt scatter diagram or snow melt curve when plotted on logarithmic paper. Statistical methods are used to compute correlation coefficients, standard deviation and probable error of the factors involved with runoff data for the snow melt season. These computations aid materially in selecting the snow survey courses best suited for the particular stream under consideration, as well as other variables showing high coefficient of correlation.
Keywords: Graphical solutions, Statistical methods, Statistics, Water supply forecasting

Chemical constituents in snow from Sierra Nevada, California to Wasatch Mountain, Utah - Rogers, S.M.; Feth, J.H. (27th Annual Western Snow Conference, 1959)
A report is presented on the results of chemical analysis completed on 98 samples of snow taken from the Sierra of California and Nevada, and also of snow from the west face of the Wasatch Mountains in Utah, as well as some samples taken form the snowpack on the Cascade Mountains of Oregon. Chlorine content analysis was made on all 98 samples. Complete chemical analysis was made on 60 of the samples representing all areas. The data are tabulated and shown, also graphical representations are included showing the relation of altitude and location.
Keywords: Chemical analysis, Snow

History of snow surveying in the west - Stafford, H.M. (27th Annual Western Snow Conference, 1959)
A chronological history of snow surveying as originated by Dr. James E. Church Jr. at the University of Nevada is outlined. This work began in 1906 with the measurement of high mountain temperatures and other climatological factors on Mount Rose, Nevada, with the Nevada Agricultural Experiment Station cooperation. The development of new instruments for measuring the snow water equivalent (water content) of the snowpack in 1909 is described. A description of the application of snow water content to water supply forecasting is presented. A resume of the importance of water supply forecasting to irrigation in the West and hydroelectric power development, reservoir regulation, flood control and water management is presented. A discussion by William A. Lang points out interesting historical details of organization and instrument development. Additional historical notations are mentioned by Walter Hopkins.
Keywords: History, Snow surveys

Use of soil moisture resistance units in water supply forecasting - Stockwell, H.J. (27th Annual Western Snow Conference, 1959)
Soil moisture measuring units are used to sample the soil moisture condition under the snowpack. The data derived is used as a correction factor in preparing water supply forecasts when using water content snow survey data. Field installation procedures are discussed as to location of measurement site and placement of units at regular intervals in the soil as a stack of units. A conversion chart of ohms resistance to percent soil moisture in the several horizons of soil are illustrated. The existing network of soil moisture stations in Colorado and New Mexico river basins are mentioned in connection with their use in water supply forecasting.
Keywords: Soil moisture, Water supply forecasting

Snow evaporation and condensation - West, A.J. (27th Annual Western Snow Conference, 1959)
Observations of evaporation from the snow surface and condensation on the snowpack were made during storm free periods over a two year season, 1958 and 1959. White polyethylene vessels were used. The bottoms of the vessels were perforated and a false bottom was attached. The entire vessels with snow were weighed to determine the loss or gain (evaporation or condensation). Temperature, humidity, and wind movement data were collected simultaneously. Observation sites were chosen in forest openings of about one-half tree height across. Forest canopy cover was measured at 70%. The resulting data comparisons are shown by tabulations, graphs and test analysis.
Keywords: Condensation, Evaporation from snow

1958 Title, Contents, and Minutes (26th Annual Western Snow Conference, 1958)

Forest shade related to snow accumulation - Anderson, H.W.; Rice, R.M.; West, A.J. (26th Annual Western Snow Conference, 1958)
Exploratory studies have been made in order to develop a system of physical measurements of forests that will more adequately index the various effects that forests have on snow accumulation. Various measurements of the forest were tested against the snow accumulation and melt at individual points within snow courses. The measurements tested from a single valued index of forest cover to a 7-variable expression of the same forest cover. The three parts of the study concern (1) the effects on snow of conventional forest variables of hemispherical cover and cover density, (2) the effects on snow of forest variables when the hemispherical cover was differentiated into shade cast by the trees to the south and shielding of radiation produced by the trees to the north, and (3) the effects of snow of several physical indexes of the forest. The measurement methods are described, the variables and their definitions are listed. An 'ideal forest' managed for water production is postulated from the results.
Keywords: Forest cover, Snow distribution, Snow research, Watershed management

Progress in snow management research in California - Anderson, H.W. (26th Annual Western Snow Conference, 1958)
A detailed outline of a snow research project underway in California towards furnishing information for watershed studies to improve snowmelt timing, equalize streamflow, reduce erosion and improve water quality through sedimentation controls. Several projects are described and available data are exhibited together with outlining the areas under study. Instrumentation of study areas are pictured and described.
Keywords: Snow research, Watershed management

Evaluation of cloud seeding efforts in the southern Oregon Cascades, 1952-1957 - Barton, M.; Calvin, L.D. (26th Annual Western Snow Conference, 1958)
Cloud seeding operations for The California Oregon Power company have been conducted by North American Weather Consultants for the past 7 years in the Southern Oregon Cascades. The purpose was to increase the mountain snowfall and consequently, the summer streamflow for the production of hydroelectric power. The seeding methods and the climate of the areas are discussed. Based on regression and isopercentile analyses of the data for the first 6 years of seeding, the following conclusions were reached. (1) the average April 1 snow water content for 1952-1957 showed a 3% increase over the expected amount. (2) The average November-March precipitation for the 6 seeding years showed a 2% increase over the expected amount, a nonsignificant increase. (3) The average April-July streamflow for 1952-57 was 4% higher than expected, a nonsignificant increase. (4) for 4 of the 6 seeded years, the highest percent of normal precipitation in the State has occurred in the Fremont-Paisley area, lending strong support to the thesis that a downwind effect exists beyond the target area.
Keywords: Forecasting, Water supply, Weather modification

An approach to forecasting the spring runoff in Quebec - Cavadias, G.S. (26th Annual Western Snow Conference, 1958)
An approach to the problem of forecasting spring runoff is described with particular reference to the conditions in the Gouin Reservoir in Quebec which has a capacity of 6.5 million acre-feet and regulates the flow for the 7 hydro-electric plants on the St. Maurice River with a total installation exceeding 2.0 million H.P. The preliminary work that led to the selection of the variables is described, the individual variables are examined, and the frequency functions are discussed. The main advantages of the described method are that (1) the assumption regarding the total length of the flood period becomes unnecessary, and (2) a better understanding of the nature of the variables that influence the volume of the spring runoff is achieved.
Keywords: Fkorecasting, Procedures

Selection of best snow course points - Court, A. (26th Annual Western Snow Conference, 1958)
The hypotheses that 5 measurements should be enough to characterize the water content of the snow course and that the MEDIAN of 5 measurements should provide almost as good an index to the snow water equivalent as would their mean. Tests were made and verified by analysis in detail the individual measurements on a typical 19 point Sierra Nevada snow course for the last 15 years of record. The history and reliability of such snow course measurements are discussed.In discussion Mr. C.G. Wolfe and Mr. J.F. Hannaford defend the views of the field man's point of view that snow survey courses of fewer point samples would prove more economical and should provide safety point of view.Also the office forecaster would much rather have 5 samples taken at 500 or 1000 feet intervals up a basin, rather than 15 or 20 taken at one altitude.
Keywords: Snow course analysis

The economics of water supply forecasting - Dwyer, C.H. (26th Annual Western Snow Conference, 1958)
A discussion of the economic value of water supply forecasting is presented dealing with monetary values. It is pointed out that if 'Economics is the science concerning the production, management, and distribution of wealth', then truly water to the farmer, in irrigated areas, is true wealth. This depending entirely on the possibility of furnishing reliable information as to data relating to: too much water or too little, together with time of delivery. It is pointed out that floods can be a liability without the foreknowledge of occurrence, and a credit if proper facilities are available for water management and planning through accurate information. An actual shortage season is described on one irrigation district where a savings of $378,850 was saved by adhering to the water supply forecasts and applying good water management to produce good crops despite the water shortage and the season was not a total loss.
Keywords: Economics, Forecasting, Water supply

The optimum use of water for power calculated by Datatron electronic computer - Ellis, J.D. (26th Annual Western Snow Conference, 1958)
A description of the use of electronic computer for routing procedures of water supply of the Lewis River in southwest Washington for hydro-power development along a series of 7 plants, is presented. The computer complex is described and read-out sheets are shown to present the data available to the operator of reservoirs and to meet the power demands.In discussion Mr. David Rockwood describes electronic computer procedures carried on by the Corps of Army Engineers in the North Pacific Division Office at Portland, Oregon. He mentions the many advantages of Automatic Data Processing machines where large amounts of the data must be handled in a short time.
Keywords: Electronic computer, Hydro power, Water management

Use of snow survey data by soil conservation districts - Fredericksen, D.C. (26th Annual Western Snow Conference, 1958)
The farmer water-users are taking an active part in the Soil Conservation Service Districts in the Western States. A large number depend on snowmelt water for irrigation, reservoir storage, and water management. They are taking a keen interest in water supply forecast committee meetings and forecast bulletins issued primarily for localized use. These local bulletins and committee meetings show a marked economic impact on the farm crop planning, particularly when there is a short supply of water. Savings in farm operation can amount to as much as $378,850 in one year in one Conservation District by, (1) saving on land preparation, (2) selection of crops that use small amounts of water, and (3) good water management. Although this case may be an ideal situation, other Districts can show a great savings by proper farm management and water conservation through the use of the localized forecast bulletin data.
Keywords: Economics, Farm irrigation, Water management

Graphical method for determination of area-elevation weighting of snow course data - Hannaford, J.F.; Wolfe, C.G.; Miller, E.W. (26th Annual Western Snow Conference, 1958)
The paper discusses the forecast schemes used by the California Cooperative Snow Survey to forecast runoff during the April-July snow melt season, the problems encountered in the use of such schemes, and the basic considerations in the evaluation of a snowpack. The basin selected for study (Yuba Basin ) and the methods of evaluating the snowpack are described, snow survey data from the evaluating the snowpack are described, snow survey data from the basin are compared graphically, and a revised forecast scheme is presented. The results indicate that the evaluation of the snowpack on the basis of only a few selected courses may lead to unrealistic results. Graphs and explanations are shown to adjust the original forecast to include 5 independent variables. (1) Snow pack index adjusted for area-elevation, (2) varying precipitation and soil priming factor, (3) runoff occurring prior date of forecast, (4) antecedent conditions, (5) forecast period precipitation estimate.
Keywords: Forecasting, Graphical analysis

Winter snow observations on Mt. Olympus - LaChapelle, E. (26th Annual Western Snow Conference, 1958)
A report of glaciological studies of the Blue Glacier on Mt. Olympus in north west Washington on the Olympic Peninsula is presented, in connection with the Geophysical Year Program 1957-58. Historical and geographical history and a description of the glacier are given. Seismic and boreholes data indicate the depth of 900 feet for the glacier. Other detailed information is given. A year round study was conducted of meteorological conditions, wind, temperature, humidity, rainfall, snowfall, ablation and spatial and temporal variations in snow albedo were recorded. Data are discussed in the text and tabulations are included.
Keywords: Glaciers, Research studies

Evolution in derivation of seasonal streamflow forecast procedures - Van Horn, O.B. (26th Annual Western Snow Conference, 1958)
A streamflow forecast procedure for the Missouri River Basin, to meet the needs of the Corps of Army Engineers Division office at Omaha, Nebraska is described in detail. Snow survey and precipitation data were analyzed by automatic data processing system (ADPS). Problems encountered during the electronic computer developing the multiple regression equations are discussed, primarily the coding and decoding and negative values of multiple correlation coefficients. Tests were made for minimizing the effect of 'local Anomaly' and negative values are described. A system of dividing the Missouri Basin into snowmelt basins from predominantly rainfall basins proved satisfactory values for coefficients. The resulting scheme provided results well within the 20% limits.
Keywords: Electronic computers, Forecasting, Water supply

Basic data characteristics in relation to runoff forecast accuracy - Work, R.A.; Beaumont, R.T. (26th Annual Western Snow Conference, 1958)
An analysis is presented of runoff forecast methods and their accuracy, and the distribution of errors by algebraic sign. The results stress the importance of basing river flow forecasts on data obtained as close to the water source as possible. Data of the most simple and direct character are more efficient. The basic data, as gathered by snow surveys from the heart of the water producing areas generally result in the most accurate forecasts because is a more precise method of sampling the greatest factor in streamflow production in mountainous western areas.NOTE: A table showing the discrepancies between two basic principals of water supply forecasting was misplaced at the time of printing, but is shown in the 1959 Proceedings of the Western Snow Conference on page 34.
Keywords: Accuracy, Forecasting

1957 Title, Contents, and Minutes (25th Annual Western Snow Conference, 1957)

Snow on forest slopes - Anderson, H.W.; Pagenhart, H.N. (25th Annual Western Snow Conference, 1957)
An analysis of snow cover distribution, depth and water content, listed according to storms or dates, terrain characteristics and forest types and percent cover is presented. Data collected by Cooperative Snow Investigations (see WSC Paper No. 199-48). The data collected from 32 snow survey courses was catalogued into categories as listed. Statistical methods were applied and the values of various statistical parameters are tabulated and shown on graphs to express the results of the analysis.
Keywords: Runoff, Snow cover distribution, Snowmelt

Runoff forecasting and snow surveying in Chile - Arias, E.S. (25th Annual Western Snow Conference, 1957)
A description and report of hydrographic conditions in Chile, South America, where snow survey course networks are being extended to meet the increasing demands for forecasting streamflow and for reservoir regulation for hydro-electric power operations and future developments, with multipurpose projects involving flood control, irrigation and municipal water supplies.Snow survey procedures and water forecasting methods have been studied in the western United States to take advantage of the highly developed programs in operation.
Keywords: Forecasting, Snow survey networks

Watershed management and water yield - Burgy, R.H. (25th Annual Western Snow Conference, 1957)
Water conservation practices are described that produce more and better quality and quantity of water from rainfall and snowmelt. Studies that result in greater contribution of water from an area for a given set of soil conditions, geologic conditions, vegetative characteristics and climate. Vegetation densities are studied for balancing water yield from medium altitude zones of brush land where 25 years of records are available. Plot studies proved inadequate and as a result pairs of small watersheds were substituted that proved to produce more responsive data. A tabulation is included showing values and types of vegetative cover, soils and treatment applied. Data are also shown in graphical diagrams.
Keywords: Watershed management

Graphical forecast errors - Burns, J.I.; Strauss, F.A. (25th Annual Western Snow Conference, 1957)
A graphical forecasting procedure is described in which 9 dependent variables are used, through a series of graphs designed into a nomograph pattern. A discussion of the several variables and references to statistical methods and parameters is set forth. Levels of accuracy and probable levels of accuracy are solved graphically. An actual forecast is presented to illustrate the scheme is shown with forecast tabulation tables to determine the weighted factors for entering the various steps in the graphs.
Keywords: Forecasting, Graphical analysis, Water supply forecasting

Maximizing river basin benefits by conjunctive operations of surface and ground-water reservoirs - Clendenen, F.B. (25th Annual Western Snow Conference, 1957)
The use of underground storage of water as an integral part of the California State Water Plan is discussed in conjunction with surface reservoir storage. Reference is made to reports by the state Department of Water Resources and the state Water Resources Board. The benefits of potential storage for sub-surface water as related to power development, fisheries and agriculture are brought out. A plan for conjunctive operational program using both types of storage is proposed with economic and conservation of water playing an important part in the over-all plan of operation. Graphs illustrate the advantage of conjunctive planning.
Keywords: Groundwater hydrology, Water plan operations

Wind direction during snowfall at Central Sierra Snow Laboratory - Court, A. (25th Annual Western Snow Conference, 1957)
How the wind blows during periods of snowfall is important in understanding the manner in which snow accumulates among trees and in open areas, and on slopes of varying inclination and orientation. Winds are predominantly southwesterly when snow falls at the Central Sierra Snow laboratory near Donner Pass. The valley of Castle Creek in which the laboratory is situated has a typical mountain-valley wind regime, northwest down the valley in night and morning and southwest up the valley during afternoon and evening. Data for wind travel and direction were analyzed during the period of 1947-48 and winter of 1957 finding a marked similarity of wind direction and precipitation values. Greater portions of precipitation fell during the southwest wind directions by two thirds greater. Less than 2% of precipitation fell during calm periods. Data are tabulated and graphed on wind rose diagrams.
Keywords: Wind direction

Mechanization of the processing of climatological data - Dale, R.F. (25th Annual Western Snow Conference, 1957)
Electronic computer for Automatic Data Processing (ADP) of climatological data as applied to Weather Bureau records and other applications are discussed in length and detail. The card punching programs of the Weather Bureau in cooperation with national Defense agencies is described together with the gigantic project of assembling such data at the New Orleans unit. After World War II three programs were continued. These are listed below.(WRPC) Weather Records Processing Centers - Regional offices.(NWRC) National Weather Record Center at Ashville, NC where over 300 million cards are on file.(Land Grant College and University) weather record processing programs in cooperation with the Weather Bureau.The need and demands for card deck copying and distribution is growing by leaps and bounds by requests from many private companies, agencies and private operators. Such demands have necessitated the transfer of much of the data to TAPE operated machines for greater speed of computation.
Keywords: Data processing, Weather bureau records

Helicopters - from the fieldman's view - Dean, W.W. (25th Annual Western Snow Conference, 1957)
The U.S. Geological Survey presents an economic study of using helicopters for over-snow transportation into remote locations of streamgaging stations and snow survey courses. Data is presented on helicopter use, contracts with operators and details of the working plans for the seasons snow survey and stream gaging schedules. A tabulation of operation statistics is shown.
Keywords: Helicopters, Oversnow, Transportation

Snow removal problems in the Province of British Columbia - Dembiske, F.E. (25th Annual Western Snow Conference, 1957)
The problems of removing snow from roads and highways in British Columbia are outlined and the organization and equipment of the snow removal program are discussed. The most notable of the problems are due to the different types of snow that fall during a winter, an insufficient supply of skilled laborers, protecting the public on the roads during the winter, snow slides, winter communications and service between the districts and the snow removal headquarters, to say nothing of pressure groups. A discussion is presented on the planning of snow removal operations, organization of field crews in July together with budget data and clearances through the Provincial Departments. The most success is gained from well trained operators and selection of congenial personnel on crews together with a large portion of 'Esprit de Corps'.
Keywords: Snow removal equipment, Snow removal from highways

Some possible effects of seeding convective clouds - Dennis, A.S. (25th Annual Western Snow Conference, 1957)
In order to determine possible effects of cloud seeding, the life history of a typical shower must be considered. This paper discusses the formation of convective clouds and the formation of solid and liquid precipitation within them. It is pointed out that if the cloud forms are seeded with silver iodide, the precipitation process stars earlier, and that the seeding of convective clouds with silver iodide reduces the intensity of hail storms and can often eliminate hail entirely. It is still uncertain whether or not continuous seeding by ground generators can increase the rainfall at the ground. Selective cloud seeding requires high flying aircraft and a high degree of skill in judging the condition in the cumulus clouds. However, there is some evidence that seeding convective storms reduces their electrical activity.
Keywords: Cloud icing properties, Effectiveness of weather modification, Weather modification

The Santa Barbara randomized cloud seeding program - Elliott, R.D. (25th Annual Western Snow Conference, 1957)
The seeding program began in January 1957 and is scheduled to continue for 3 years. The organization, history, operations thus far conducted, and the manner in which the seeding is carried out under the randomizing plan are discussed. No complete statistical analysis of results can be accomplished prior to completion of the project. However, thus far (January 10 - April 12, 1957), 4 storms have occurred yielding over an inch of precipitation in the mountains. Of these, two were seeded completely and one partially. The ground based silver iodide smoke generator layout and the recording rain gage network are shown on the location map.
Keywords: Nucleation, Research program, Silver iodide, Weather modification

Lysimeter studies of snowmelt - Hildebrand, C.E. (25th Annual Western Snow Conference, 1957)
An outline that summarizes the observations of the snowmelt quantities and meteorological parameters by which the several processes of heat transfer were evaluated, are presented. the results of the study are expressed in the form of melt coefficients which sere verified by a comparison of actual snowmelt with that computed by these coefficients. Independent statistical analysis were also made. the data tabulations list the snowmelt and heat transfer parameters for each day of the period study. The snowmelt quantities were measured by a lysimeter shown in two photos. Construction drawing s are shown and tabulation of data collected are also included.
Keywords: Lysimeter studies, Snowmelt research

Reservoir evaporation control - Kerr, R.E. Jr. (25th Annual Western Snow Conference, 1957)
The general background and review of the science dealing with evaporation control is presented, with the hope that effective application to large reservoirs will be successful. Experimental research projects are reviewed, dating back to 1925 where using products of alcohol derivatives would form a monomolecular film over the surface of the water to control evaporation. Considerable work published on such methods are cited as well as experimental projects underway in the United states, England an Australia. Laboratory experiments indicate a 99.99% reduction in evaporation but field work will probably show a reduction of 20 to 45%. A list of 14 references accompany the paper.
Keywords: Evaporation control, Evaporation research, Reservoir evaporation

Water supply forecast developments, 1951-1956 - Kohler, M.A. (25th Annual Western Snow Conference, 1957)
A review of mathematical procedures used developing forecasting formulas and procedures from 1951 through 1956, is presented. Procedures are shown to follow an approach to solve the 'water budget' equation of stream outflow from a river basin is equal to the inflow minus the changes in storage. This general formula is expanded to include 12 of the variables listed for a water year forecast and 13 of the variables listed for an April-September runoff period forecast. The snowpack data is added. A discussion of the factors is indicated in the text.An annotated bibliography is included of 23 technical papers dealing with water supply forecasting.
Keywords: Forecasting water supply

An application of snow survey data to glacier research - Meier, M.F.; Simons, W.D. (25th Annual Western Snow Conference, 1957)
Snow surveys of a more complex procedure than usual are used in conducting research on glaciers to determine; (1) an understanding of the hydrology of glacier covered regions and (2), the use of glaciers as quantitative indicator of climate. Research project information gathered by the Geological Survey indicate the possibility of a backward look at climatic factors of past years. Data trends shown graphically for snow accumulation or ablation of the glaciers. Snow surveys on the glaciers at times use standard tubes but more often dig pits into the snow covering the glacier to ice, then use machine core drills for deep examination of the strata of the glacial ice.
Keywords: Glacier research, Snow cover on glaciers

Ceilings unlimited - Miller, R.W. (25th Annual Western Snow Conference, 1957)
A report of the advantages of helicopter travel as a means of reaching remote snow courses by snow surveyors of the Department of Water Resources, California is presented. With the advancement of helicopter design and construction this mode of over-snow vehicle is being used extensively and sufficient data has been accumulated to attack the problem from an economic standpoint, as compared to foot travel and over-snow surface vehicles. The saving s of time such as measuring 10 snow survey courses in one day as compared with 10 back breaking days by foot travel. Of course advantage must be taken of weather for flying. There seems to be no way to evaluate safety as both means of travel have their own safety hazards, and manpower fatigue falls into this same category. Large savings are made in eliminating overnight cabins, construction and maintenance. the speed with which data can be transmitted to the forecasting office has some consideration.
Keywords: Economics, Helicopters, Transportation

The use of Fourier series in streamflow forecasting - Milligan, C.H. (25th Annual Western Snow Conference, 1957)
A new approach to streamflow forecasting is described clearly but briefly in using the Fourier Series as a forecasting tool. A complete array of data is tabulated for the Logan River near Logan, Utah, using four (4) independent variables:(1) Daily and average monthly temperatures at valley stations(2) Daily and monthly precipitation at valley stations(3) Daily and monthly streamflow(4) April 1 snow survey data at 7 mountain stations in the Logan River drainage.Fourier Series coefficients are developed for these variables and applied to the 1956 field data. The resulting forecast for that year was only in error by 9% of the observed runoff.In discussion Mr. George R. Hamburg and Mr. H. Boyd Phillips pointed out the advantage of this seldom used forecast procedure for working with inflow to reservoirs.
Keywords: Forecast procedures, Fourier series

Water supply planning for multi-purpose reservoir operation - Reynolds, R.R.; Kennedy, D.V. (25th Annual Western Snow Conference, 1957)
A discussion of problems involved in operating the facilities of the California State Water Plan is presented. Reservoir storages are operated to obtain the maximum flood protection as the prime function together with meeting the other demands of the multiple use project of controlling streamflow for navigation, irrigation, hydroelectric power production, salinity control, municipal water supplies, fisheries management and recreation needs. In California most of the water in the many streams has been allocated by water rights. Strict economy of water use must be exercised and further planning must be continued towards equal opportunity for unpolluted water to meet the increasing needs and demands of an expanding population and industrial growth.
Keywords: Multi-purpose reservoir planning, Reservoir regulation

Research required to make cloud seeding a quantitative science - Todd, C.J. (25th Annual Western Snow Conference, 1957)
An approach to putting practical cloud seeding on a valid engineering basis is described. The main problem is the development of precipitation graphs from which is possible to (1) compare the difference in rainfall resulting from differing concentrations of freezing nuclei, (2) determine the optimum seeding concentration for the class of cloud in question, and (3) determine the cloud seeding potentialities of a given watershed from previously obtained data, by observational and computational procedures. Planning procedures and theorems are described. Examples of graphs are exhibited showing the theoretical time of precipitation initiation when the initiation is by the warm cloud condensation coalescence process or the ice crystal process.
Keywords: Clouds icing properties, Research, Weather modification

New meteorological and snow studies in the Central Sierra - Walsh, K.J. (25th Annual Western Snow Conference, 1957)
A description of the re-activation of the Central Sierra Snow Research Laboratory in 1956 by the U.S. Forest Service, California Forest and Range Experiment Station, Berkeley, California, in cooperation with the state Department of Water Resources at Sacramento, California is announced. Details of project plan and selection of data to be collected and areas of activity for investigation are described. Basic meteorological elements as measured by the corps of Engineers and Weather Bureau Cooperative Snow Investigations will be continued and plans to expand activities are discussed.
Keywords: Snow research programs

Rime ice and snow capping on high altitude precipitation gages - Warnick, C.C. (25th Annual Western Snow Conference, 1957)
Shielded storage precipitation gages are shown difficult to operate efficiently in areas where snow storms occur at moderate temperatures (about 35 to 25ºF) with little or no wind. such conditions cause the snow to cling to metal and cap the gage orifice, no matter how large or small: also efficient operation is hampered by formation of rime ice on metal when exposed in a windy location at critical temperatures, especially in cloud covered areas. A heating element in the orifice of the gage to overcome these conditions is described and delineated in drawings. Experimental data with this heated orifice gage is exhibited covering a period 1951 through 1957. A discussion of experimental data is included with recommendations and cost data of gage and pertinent equipment.
Keywords: Capping, Heated orfice, Precipitation gage, Rime ice

Variation in streamflow from different hydrologic zones - Wilson, M.T. (25th Annual Western Snow Conference, 1957)
Streamflow of rivers or the flow of different reaches of the same stream are discussed. Streamflow is a residue, it is the remainder of the precipitation after natural losses and normal use of the original quantity have been subtracted. The principal factors affecting the residue (streamflow) are transpiration, evaporation, deep percolation, soil moisture, and interception. The 'same hydrologic zones' is used to express sameness in precipitation, altitude, geology, and vegetative cover and other major factors that control the runoff characteristics. The 'double mass diagram' is employed to show the variation of streamflow derived from various zones, influenced by a change in factors describing the zones. Results of this procedure are used to fill missing streamflow data for secondary gaging stations, from data measured at a primary station.Discussion by F. B. Blanchard.
Keywords: Flow analysis, Hydrologic zones

Snow surveys from the snow surveyors' side - Wycoff, P. (25th Annual Western Snow Conference, 1957)
An article describing the feelings of the snow surveyor, the person who travels miles on skis or snow shoes and measures the snowpack at snow survey courses to obtain snow water content and snow depth. The frustrations and delights of this work are enumerated. A plea is made for more detailed planning towards better overnight cabin facilities and foods. Details of desired improvements in snow surveyor training, communications, sampling equipment, and general respect for the field mans attitude towards the work and general procedures are discussed.
Keywords: Snow survey procedures

1956 Title, Contents, and Minutes (24th Annual Western Snow Conference, 1956)

Forecasting Powell Lake runoff - Chard, A.E. (24th Annual Western Snow Conference, 1956)
The method for forecasting runoff in this British Columbia watershed (580 sq. Mi.; to 7000 feet elevation) is described. The source of data forecasting were snow surveys, precipitation records at the townsite of Powell River, and long-range weather forecasts. An empirical runoff formula was developed from snow survey -precipitation data and curves were constructed showing the net runoff to be expected form the snow water content at the snow courses. The contribution of snowmelt was found to be 1/3 of the total runoff. A sample calculation of expected runoff for 1956 is presented.
Keywords: Forecasting

Report on snow surveyors training conference at Alta, Utah - Davis, R.T. (24th Annual Western Snow Conference, 1956)
Snow Surveyor Training Conferences are sponsored by the Soil Conservation Service, U.S. Department of Agriculture every two years in mid-January. The conferences are held at some ski lodge or winter recreation center where actual snow survey techniques and winter survival can be taught to men who are going to do this specialized work in remote locations of the mountains of the western United States, Australia, Pakistan, India, and South American countries. The 85 to 120 men are divided into groups and specialists in the various techniques of snow surveying teach their specialty. Cross country skiing and snowshoeing, winter survival, winter first aid, and rescue operations. Considerable time is spent on the techniques of snow sampling to obtain accurate results, and a comprehensible set of field notes on snow conditions. Evening classes include lectures on the use of snow survey data and visual aids of avalanche detection and rescue operations. Men are required to spend one night in 'bivouac' to learn how to sleep in the snow, to allay fears of outdoor living.
Keywords: Avalanche rescue, Safety, Training, Winter survival

The snow research program at the Fraser Experimental Forest, Colorado - Goodell, B.C. (24th Annual Western Snow Conference, 1956)
The results of past studies on the relation between snow and forests are reviewed and tabulated, and problems of future research are discussed. The forest is located about 6000 feet elevation and has an average annual precipitation of 30-40 inches, 60-80% of which is in the form of snow (which accounts for 80-90% of the annual streamflow). The first studies conducted were concerned with the relation between snow accumulation and the size of openings in various types of forests, and the effects of deforestation with snow evaporation; the question whether evaporation from intercepted snow is actually sufficiently faster than from the pack surface to account for the apparent gain in snow when trees are cut; the blowing of snow from tree crowns, and its possible sublimation during transit. Other projects will include: convection and condensation during snowmelt, the effects of tree trunks and small trees on snowmelt, the hydrologic effect of any forest management practice, and the water yield from alpine snowfields.
Keywords: Research problems, Snow cover distribution

Multiple-graphical correlation for water supply forecasting - Hannaford, J.F. (24th Annual Western Snow Conference, 1956)
The method described and a sample forecast for the Feather River, California is presented. The forecast formula or graphs are based on data for the April-July spring runoff period, during which the majority of snowmelt runoff occurs. The general parameters used include: the measured water content of the snowpack at high elevations, the carryover from previous years in the form of ground water, and late season precipitation. A 'percentage of normal' index (the normal based on a 50-year period) is used to convert raw data into a form readily adaptable for use in the multiple graphical relationship, permitting rapid calculation for an approximate forecast. Data on the normal precipitation and snowpack expectancy are graphed, and forecast diagram and forecast computation form for the Feather River are included.
Keywords: Forecasting, Graphical techniques

Snow hydrology summary report - Johnson, O. (24th Annual Western Snow Conference, 1956)
The Corps of Army Engineers, North Pacific Division, at Portland, Oregon, in cooperation with the U.S. Weather Bureau have produced a report of field studies completed by the Cooperative Snow Investigation program. These studies were conducted by the two agencies at three snow laboratories in differing climatic conditions in the Sierra Nevada, Cascade and Rocky Mountain areas. This report deals with the many problems involved in snow hydrology. The summary report consists of 12 chapters. Detailed text of the report includes tabulated data collected, graphs and formula development for solving complicated theories. An outline of the 12 chapters is included.Copies of this report are available from the Division Engineer, Corps of Army Engineers, Portland, Oregon.
Keywords: Hydrology, Research programs

Thermodynamics of transpiration in heavy forest during active snowmelt - Mondrillo, G. (24th Annual Western Snow Conference, 1956)
The thermodynamic relationships involved in forest transpiration in snow covered areas during non-advective weather are analyzed using data from the 1949 melt season (May 9-13) in the Willamette Basin Snow Laboratory and assuming that net advection, net basin energy change, and net moisture content change of the air and soil are nil. The energy used for transpiration is computed as the difference between the net all-wave energy change with space and the energy required for melting snow. The transpiration loss is found to consume about 50% of the net input energy to the basin, amounting to an average of 0.14 inches/day (about 10% of melt) for the period investigated. Condensation water undergoes a repeated cycle of evaporation and condensation, aiding the transpiration process by supplying water to vegetation and aiding the transpiration process by supplying water to vegetation and aiding melt by returning some of the total transpiration energy to the snow. Data on the magnitude of the processes involved in the transpiration loss, including melt components are tabulated.
Keywords: Snow research, Thermodynamics of snow

A modern forecast for Columbia River at Birchbank, B. C. - Nelson, M.W.; Simons, W.D. (24th Annual Western Snow Conference, 1956)
A highly refined and straight forward procedure is described for developing seasonal (April-Sept.) water supply forecasting formulas for the Columbia River at Birchbank, B.C. The formulas are checked by 3 years of data NOT included in the data used to develop the equation.For the April first forecast a formula was developed using 7 snow survey courses and base flow of the river as of November 1. Current values for these variables are available to the forecaster on April first.For the May first forecast a third variable was added, the precipitation data of April, the average of 7 stations was computed. On June first a fourth variable was added, the May precipitation from the same 7 stations was averaged. For the three comparative years the average error for the April forecast was 5.5%; May forecast 3.9%; June 3.3%.Table shows the array of data used in the formula development and accuracy comparisons are shown.
Keywords: Baseflow, Forecasting

Work accomplished to date by the advisory committee on weather control - Orville, H.T. (24th Annual Western Snow Conference, 1956)
This second report by the Advisory Committee on Weather Control, (first report see WSC No. 266-54), points out two striking incidences in weather modification: (1) snowpack increase by seeding operations in mountainous areas of the West during favorable weather conditions, and increases in precipitation of 9% to 17%. (2) Suppression of lightning and forest fires and also hail storms by the use of cloud seeding operations covering seven Western states. Such success is shown to be of economic benefit to hydro power development, agriculture and other multiple water use projects.A long time evaluation program has been set in motion by enlisting the assistance of commercial cloud seeding operators. Committeemen are making on the spot evaluation by contacting farmers, ranchers, fruit growers, and municipal water officials to gather evidence for or against cloud seeding.
Keywords: Evaluation, Weather modification

Runoff characteristics of the Columbia and Kootenay Rivers in British Columbia - Raudsepp, W. (24th Annual Western Snow Conference, 1956)
A detailed description of hydrologic data and basin features of the subject rivers above Birchbank, Canada is presented. Tables are included to show the relative areas of the tributary basins above the principle gauging stations, together with the average annual runoff from these areas. Data and size of peak to average annual flow are shown graphically.
Keywords: Basin characteristics

Problems of snow removal in mountain passes for 1955-56 - Stackhouse, J.L. (24th Annual Western Snow Conference, 1956)
The causes for difficulties in Washington and countermeasures are described. The 3 major factors causing problems are snow slides and avalanches, people, and the breakdown of equipment. In the winter of 1955-56 maximum snow depths were recorded as follows; 18 feet on Mt. Baker, 18 feet 3 inches on Snoqualmie Pass and 14 feet 10 inches on White Pass. Fairly good results were obtained by triggering avalanches with explosives. The snow equipment used on all passes consisted of push and V-type plows, blade plows with serrated bits, rotary plows, mechanical sanding equipment and mobile truck power shovels for removing deep snow slides. Equipment failures are frequent due to rough usage, especially with Snogo units, because of the delicate mechanism of their blower fans. Cost of snow removal are quoted as: Washington statewide figure, $246 per mile for 1954-55, Stevens Pass, $4,984 per mile, Snoqualmie Pass, $8,246 per mile and White Pass, $2,588 per mile.
Keywords: Highways, Snow removal

A field determination of free water content in wet snow - Williams, G.P. (24th Annual Western Snow Conference, 1956)
The results of investigations and tests of a method for determining the free water content of snow by measuring compacted density are reported. Best results were obtained by inserting snow loosely in one inch layers in a 250 cc. container and tamping each layer 4 times by dropping a 1 kg. weight 10 cm. A good relation was found between free water content and compacted density, especially for settled and coarse spring snow as well as water content above 5%; below 5% there was more variation in the relationship. The rate at which compacted density increases with water content above 5% was compared for different types of snow. Fine-grained snow tended to compress to a higher density than coarser snow. The advantage of the method is that it gives information on the physical structure of wet snow during the tests.
Keywords: Free water content, Snow quality, Snow research

1955 Title, Contents, and Minutes (23rd Annual Western Snow Conference, 1955)

Operational economy through applied hydrology - Blanchard, F.B. (23rd Annual Western Snow Conference, 1955)
A water supply forecasting scheme to define and illustrate the general principles governing the economics of operation for hydropower plants, reservoirs, and certain other water works are shown. The many alternate selections of operating schedules are explained and shown by examples of actual data. Water supply forecasts are an important factor in these estimates to produce the maximum of returns to the operators. Antecedent precipitation and precipitation frequency charts are illustrated together with percentile positions to enter a nomogram to arrive at the moneys to be anticipated from an assumed schedule of operation. Several trial runs must be made and judged by the results as to which schedule is the most feasible to follow. A general outline for the procedure is shown in a list of 8 steps to be followed.
Keywords: Economics, Hydrology

Establishing snow survey networks and snow courses for water supply forecasting - Codd, A.R.; Work, R.A. (23rd Annual Western Snow Conference, 1955)
The purpose of snow surveys and the planning of survey networks are discussed. Factors determining the type of snow course network, the number of snow courses, and measurement schedules are outlined. Criteria for the selection of the snow course location are examined, including; elevation, water production of the area, relation to other snow courses, accessibility, and the physical characteristics of the site. Conditions influencing the accuracy of snow, the number of snow samples taken, the relation between the snow course and its environment, and the marking of sampling points are considered.Discussion by J.H. Doughty-Davies and F.M. Veatch.
Keywords: Networks, Snow Courses, Water Supply Forecasting

Watershed management opportunities in the west (Abstract only) - Colman, E.A. (23rd Annual Western Snow Conference, 1955)
A discussion is presented relative to the conservation of water producing areas of the State of California, to meet the anticipated needs of expanding population, agriculture and industrial development. The water producing areas of the state are divided into 4 zones: (1) the brushland belt occupying 17.5% of the state's area and producing 12.0% of the water supply, (2) the timber belt below the snow line 3,500 to 5,000 feet elevation comprising 12.5% of the state area and supplying 33% of the state's water supply, (3) the timber belt zone in the snowpack area with 9.0% of the state's areas and produces 38.0% of the water supply, (4) the alpine zone covering 3.0% of the state's area produces 14% of the water supply. Conservation practices are outlined for water and snowpack management in these zoned areas for planning more economical use of the products of water supply.
Keywords: Watershed management

Observations on the Nisqually glacier, Washington and Grinnell, Jackson, and Sperry Glacier, Montana - Giles, G.C.; Colbert, J.L. (23rd Annual Western Snow Conference, 1955)
Data collected during various periods back to 1857 on the terminal recession, changes in surface elevation, and surface movement of these glaciers are discussed. Nisqually Glacier receded about 4900 feet since 1857 at an average rate of 50 feet per year. The surface elevation has risen 83 feet between 1945-51. Other detailed data is included since more interest has been shown in glacier activity. Little change has been observed in Sperry and Grinnell although Grinnell has retreated 30 to 40 feet per year since 1949. Sperry is considerably less active.
Keywords: Glacier research studies

Use of electrical soil-moisture units in mountain soils - Horton, J.S. (23rd Annual Western Snow Conference, 1955)
A procedure for measuring soil moisture at several depths in a mountain soil mantle using fiberglass, monel metal units (Colman Units) is presented. These units have a thermister (temperature element) encased in the monel metal case. Three wire leads are brought to the surface through a pipe to prevent rodent damage. The meter is an alternating current design circuit to measure impedance In milli-amps, thus averting a direct resistance reading that would be contaminated by soil salts or acids. The milli-amps readings are converted to Ohms by a calibration chart furnished with each meter. The process of calibrating the units to soil moisture by field and laboratory procedures is discussed. Calibration curves are exhibited. A discussion of results is included in the text of the paper.
Keywords: Colman units, Soil moisture measurements

An instrument for measurement of the density of plant cover over snow course points - Ingebo, P.A. (23rd Annual Western Snow Conference, 1955)
An instrument and method of measuring the percent of vegetative cover, (forest canopy cover, overstore cover) are described and illustrated. The instrument consists of an inverted aluminum frustum of a cone with diameters of 12 and 6 inches. A silver ball is centered near the bottom and an eye piece is mounted on one side to observe the reflection of the hemisphere on the silver ball. A dot-grid is mounted on the top 12 in. diameter, the grid is quartered and circles at 15 deg, 30 deg, and 45 deg from the vertical are drawn on the grid. By looking through the eye piece the dots that are covered by trees or leaves or needles are counted by quadrants and segments and tabulated. The instrument is leveled and oriented (N). A graph illustrates the percent canopy cover to percent of snow accumulation in the open and under the trees of differing percent cover as a result of some 750 observations. In discussion Dr. Paul E. Lemmon describes a similar hand held instrument.
Keywords: Canopy cover measurement

Forecasting natural runoff in relation to pumping for irrigation - Peak, G.W. (23rd Annual Western Snow Conference, 1955)
An illustration is cited of the economic value of snow survey water supply forecasting, for an irrigation project dependent upon reservoir storage from snow melt or pumping from the Flathead River with a fixed maximum load rate. The lower the maximum load, the lower the yearly power rate. Water supply forecasting is accomplished using snow survey courses in the Mission Range in western Montana, and other hydrologic variables, temperature and fall precipitation. A series of multiple regression formulas were developed for forecasts to be made on March, April, May and June. In the spring of 1950 cold weather delayed the runoff well beyond the usual May and June dates. Low snow had disappeared into the soil and the prospects for sufficient snow water looked bad, even in the face of snow survey data for April showing an above normal water content. Starting the pumps would throw the power rate for the year into the highest bracket. Faith in the forecasts prevailed, and on July 2 warm temperatures arrived, canals and reservoirs were full and all reservoirs were filled in one week. Actual money savings of $35,000 in power bills was made.
Keywords: Economics, Forecasting, Natural runoff

A review of the first 10,000 abstracts by the SIPRE bibliography project - Sherrod, J. Jr. (23rd Annual Western Snow Conference, 1955)
The Snow Ice and Permafrost Research Establishment (SIPRE), Corps of Engineers, U.S. Army, through its support of the SIPRE Bibliography project at the Library of congress, is preparing and publishing abstracts of all technical literature on snow, ice and frozen ground. The details of this extensive project is explained, as well as the type of material abstracted and catalogued for reference. Translations of papers published in foreign languages are also included in the project. A table of time and language distribution of papers is shown. The abstracts and reference material is published in book form, 8x101/2 paper cover and staple bound, with 1,000 to 1,500 abstracts per volume.Bibliographer's Note: These abstracts are also duplicated on 3x5 library reference cards. The above volumes are released in January and July of each year and as of 1965 there are 25 volumes. An accumulative index CRREL report No. 12 was released in June of 1964, however, each volume has its own index. At this time there are approximately 40,000 abstracts prepared and published on a variety of more than 4,000 subjects.
Keywords: Abstracts, Bibliography

The program of surface water ingestigations in the west - Wells, J.V.B. (23rd Annual Western Snow Conference, 1955)
A discussion was presented of the detailed procedures used by U.S. geological Survey to produce their Water Supply Papers. Present methods are described and mention is made of a project to bring early published data up to present day standards, and republished. Mention is made of the Current Records Centers and their procedures to furnish daily, monthly streamflow data to operation agencies and companies. Attempts are being made to speed up the issuance of data by using electronic integrators and data processing equipment as a means of increasing accuracy and meet the demands of data users.
Keywords: Electronic data processing, Stream measurements, Surface water

Reconstruction of the snow-melt hydrograph in the Payette River Basin - Zimmerman, A.L. (23rd Annual Western Snow Conference, 1955)
A recently developed method of forecasting runoff of streams where snowmelt is the predominant factor in the flood hydrograph is described. This procedure was developed on the basis of data for the years 1943-45 and 1950-52, which included both large and small seasonal volumes and high and low peak flows. Radiosonde temperatures provided the basis for most of the temperature parameter, and daily increments of total computed runoff from snowmelt and rain were divided into 2 components: surface runoff and ground water runoff. The method permits computation of an entire seasonal hydrograph without reference to the observed hydrograph, once the snowmelt season has begun. Other day-to-day factors are involved. The procedure was tested on the Payette River, Idaho with satisfactory results.
Keywords: Flood hydrograph development, Forecasting

1954 Title, Contents, and Minutes (22nd Annual Western Snow Conference, 1954)

Volume inflow forecasting procedures, Hungry Horse Reservoir, Montana - Bissell, L.M.; Earl, K.D. (22nd Annual Western Snow Conference, 1954)
Several streamflow forecasting formulas are developed using combinations of several possible variables. (1) Precipitation only, (2) snow courses and precipitation, (3) snow courses, precipitation and base flow. A statistical comparison with the usual parameters is presented to show the weight carried by each independent variable. In discussion Mr. Harold Hafterson and Mr. R.E. Lindgren indicate several improvements in using short term records. The April-September precipitation as an independent variable is difficult to evaluate when the forecast is made on April first, where the forecaster must use a normal or average figure, or attempt to estimate a plus of minus normal figure. This variable alone carries a large weighting factor and a misestimate could spell disaster in forecasting the inflow to Hungry Horse Reservoir.
Keywords: Streamflow forecasting

Heat exchange and melt of late season snow patches in heavy forest - Boyer, P.B. (22nd Annual Western Snow Conference, 1954)
An analysis is presented of observations in mid-July over a continuously melting snow patch in a dense forest during five days of clear, calm weather. Each heat component is evaluated from measurements (and supplementary estimates), of long-wave and short-wave radiation, of free air temperature and humidity at a meteorological station, and on rather crude measurements of condensation and of air temperature gradients close to the snow. The snowmelt equivalent of heat supply is compared with measured ablation. Approximately 50% of melt at the snow surface was due to long-wave radiation, 20% to convective heat, 15% to latent heat of condensation and 15% to short-wave. Thus, 85% of the melt was accounted for by air temperature and humidity, ordinarily available at a meteorological station, and 15% by short-wave radiation which can be estimated from records of insolation elsewhere. The results of the study are formulated in a melt equation involving only linear functions of air temperature, humidity and short-wave radiation.Discussion by Walter U. Garstka.
Keywords: Snowmelt research

Use of aircraft in snow surveying - Codd, A.R.; Nelson, M.W. (22nd Annual Western Snow Conference, 1954)
The advantages and disadvantages of using airplanes in snow surveying are described and comparative cost data for overland surveying are tabulated. Airplanes are successfully employed on several snow course at the present time. The chief obstacle to their use is possible adverse weather conditions at the time the survey is scheduled, and the possibility of taking off from a dry airport and landing on a snow covered pasture near the snow course. Comparison indicates that the cost of measuring courses by air are more consistent, but other aspects of cost are difficult to compare. A few general specifications for snow landings at elevations from 5000-10,000 feet are given.
Keywords: Aircraft use in snow surveys, Snow survey transportation

Water yield from snow as affected by consumptive water losses - Craddock, G.W. (22nd Annual Western Snow Conference, 1954)
Watershed management procedures are shown to be effective in conserving snowmelt water, producing forage corps, reducing sediment in streams, and controlling herbaceous plants on high watersheds of the inter-mountain western region. Deforestation was found to produce only temporary relief to gain a greater snowpack that produced more water with greater transpiration and increased the silting of streams, especially during heavy summer rain storms. A grass mixture of smooth brome, timothy, Kentucky bluegrass, dandelion and sweet-sage proved the most effective soil cover and forage producing vegetation. Advantages are cited on range land in the intermountain watershed studies.
Keywords: Watershed management

Effect upon seasonal runoff forecasts of measurement errors in basic data - Dean, W.W.; Frost, W.T.; Kuehl, D.W. (22nd Annual Western Snow Conference, 1954)
A study was made of random sampling errors inherent to hydrologic data used for statistical development of multiple-linear regression formula to forecast the probable season water supply. Random errors were induced into basic data of both the dependent and independent variables and multiple linear equations were developed. The usual statistical parameters of correlation coefficient and standard error were compared with those formulas developed where the obvious random errors were NOT induced. These tests indicated that the introduction of errors in the magnitude chosen did not cause any large effects in the regression equation. It is suggested that every effort be made to gather and use data without errors in measurement and keep hydrologic data up to standard.
Keywords: Statistical analysis, Water supply forecasting

Evaluation of rain making experiments in Utah - Hales, J.V.; Hoffer, T.E.; Peck, E.L. (22nd Annual Western Snow Conference, 1954)
After three years of operations a weather modification project is studied and an evaluation is made over an area covering 200 square miles in Southern Utah. Use is made of Electronic Data Processing equipment to evaluate precipitation data from 120,000 Weather Bureau observations of daily rainfall amounts from the state. The process involved a statistical comparison of data from within and without the target area, also the inter-relationship between stations. Many problems complicate the study: the changing of location of silver iodide generators, the addition of more generators, the silver iodide drifting out of the target area and effecting station records in remote areas. It became difficult to establish a constant set of guidelines for evaluation. The studies are continuing for reporting, provided funds are available.In discussion Mr. Boyd E. Quate pointed out the difficulties of evaluating cloud-seeding operations by virtue of so many projects in operation over the arid states that the long distance effect of silver iodide particles may affect precipitation on an inter-state basis.
Keywords: Weather modification evaluation

Use of melt-season snow surveys - Koelzer, V.A. (22nd Annual Western Snow Conference, 1954)
A method of interpreting results of snow surveys after the start of snow melt is given, and use of the procedure is illustrated for a section of the North Platte River basin. This involves relating the amount of snowmelt to the amount of snow measured at given dates after the melting season commences. Regular melt season surveys are recommended for areas with present and planned substantial control structures.In discussion Mr. Homer J. Stockwell points out the need for snow survey data during the melt season. He also points out the possibility of including soil moisture data during the late season forecasts, particularly on streams where substantial control structures are planned.
Keywords: Runoff, Snowmelt, Statistical analysis

How long should gaging stations be operated? - Langbein, W.B. (22nd Annual Western Snow Conference, 1954)
During the past 50 or 60 years, the U.S. Geological Survey Surface Water Branch, has operated 12500 stream gaging stations, about half of these are active today. Those discontinued were found to be either excess or correlations with other stations could supplement the data without serious damage to the records. Consideration is being given towards this procedure at many stations. The benefit-cost ratios are being studied, where the operation and maintenance costs have gone up. The cost-benefit ratio is an important factor in how long a station should be operated. Primary stations on main rivers will, of course, be maintained. Examples of statistical methods employed are described and illustrated graphically. Optimum benefits occur in the first 6 years with maximum benefits occurring in about 15 years.The paper is discussed by Mr. Perry M. Ford.
Keywords: Hydrology stream measurements

Some upstream aspects of the 1952 Spring flood in Utah - Murray, W.E. (22nd Annual Western Snow Conference, 1954)
A report is presented dealing with a snowmelt flood that occurred through Northern and Central Utah during the spring of 1952. A team of U.S. Forest Service personnel made a detailed field inspection of the river basins affected and pooled the data to show the causes. 1) Above average snowpack extending from the high elevation down through the intermediate areas and well into the large low elevations of the basins. 2) A sudden rise in temperature on the first of April, from freezing to 80º F and warm nights for a two weeks period. 3) Fall rains had brought the soil moisture to above field capacity. Precise timing of these snowmelt factors removed the low and intermediate snow in a few days causing high peak flows. The high elevation snow being well consolidated did not appear in the streams until late in the season causing only minor and extended peaks. Tabulated data exhibited confirms snowpack extent and the timing of meteorological factors.
Keywords: Flood damage, Snowmelt

Aims and activities of the U.S. Advisory committee on weather control - Orville, H.T. (22nd Annual Western Snow Conference, 1954)
The duties and aims of the newly appointed Advisory Committee on Weather Control are explained in some detail. Reference is made to PROJECT CIRRUS, dealing with weather modification and the present state laws regulating weather modification in 7 western states and New York State. Reports of the committee will be unbiased and built on true facts of gathering and research project findings. In discussion Mr. Robert D. Elliott points out occurrences of possible bias in weather modification reports and expresses willingness to furnish information from western operators.
Keywords: Weather modification controls

Low winter streamflow as an index to short-term and long-term carry-over effects in water supply forecasting - Peck, E.L. (22nd Annual Western Snow Conference, 1954)
A study is presented of minor indices effecting annual streamflow volume forecasting in the Intermountain West. Time trend of precipitation measurements with streamflow also time trends becoming evident by gradual increases of water-use and evaporation losses. The carry over effect of groundwater storage was found to be related to size of figures representing the low-flow period or winter stream flow, i.e., February. This low-flow value is shown to be an integrator of minor indices, expressing ground water and soil moisture conditions.Mr. C.C. McDonald in discussion intimates that the date of base flow must be selected so that the actual measured flow data is available to the forecaster when needed, and that an estimated value plus or minus average will greatly effect the degree of correlation, also that the trend of streamflow is related to base flow.
Keywords: Base flow, Time trends, Water supply forecasting

Statistical analysis of streamflow relationships - Somers, W.P. (22nd Annual Western Snow Conference, 1954)
A description and illustration of correlation techniques is presented, that the U.S. Geological Survey is using in making studies of streamflow relationships. The procedures are illustrated by a study of two basins about 68 miles apart, but both having similar hydrologic characteristics, and located in northeastern Utah. Data is tabulated and analyzed on a monthly basis by statistical methods using the usual parameters as a means of comparison.In discussion Mr. R.D. Goodrich presents a solution of streamflow correlation from a different section of the country, but obtained comparable results.
Keywords: Hydrology stream measurements, Statistical analysis

The influence of ground water storage on the runoff in Southern California - Troxell, H.C. (22nd Annual Western Snow Conference, 1954)
Ground water seepage from underground water aquifers into streams has been the principal agricultural supply for many years in southern California coastal plain areas. Physiographic and climatological features of this important section of California are described. Runoff distribution of streams is depicted graphically. Ground water seepage is separated from the hydrograph of flash storms from rainfall. These methods are substantiated by experimental work done in the San Gabriel Mountains by the U.S. Forest Service at the San Dimas Experimental Forest. The subsurface water storage is estimated to produce 80 to 90 percent of the annual flow in many of the streams.
Keywords: Groundwater, Hydrology groundwater

Long range weather forecasting - Van Ornum, D.G. (22nd Annual Western Snow Conference, 1954)
Upper air current circulation at the 700 m.b. surface are studied on a hemispheric basis between the 35o and 65o north latitude parallels toward a solution of high and low pressure cells occurring over land surfaces. Effects of mountain ranges and desert temperatures to upper air current ridges and troughs are explored. Use is made of Polar Weather Charts of the Northern Hemisphere for plotting weather data from world round stations received from many countries. Results of the study are shown on graphs and is discussed in the text.In discussion, Mr. Charles Pennypacker Smith points out the value of Mr. Ornum's conception of considering the upper air currents as similar to moving water in a river, and confined between banks, is most worthwhile and is a step forward in understanding the movements of storm cells.
Keywords: Weather forecasting long range

1953 Title, Contents, and Minutes (21st Annual Western Snow Conference, 1953)

A systematized regression forecasting method - Barton, M. (21st Annual Western Snow Conference, 1953)
A statistical method is presented for developing an up-to-date streamflow forecasting formulas. The primary purpose being to assist the streamflow forecasters to prepare their data in a logical procedure with close checks as the complicated process of multiple regression development proceeds. Such a procedure enables the operator to detect any shift in the relationships and make corrections. A series of 9 tables illustrate the procedure.
Keywords: Statistical analysis, Water supply forecasting

U. S. Weather Bureau snow cover observation program - Butson, K.D. (21st Annual Western Snow Conference, 1953)
Photographic observational techniques for snow surveying the Columbia Basin, under study by the weather Bureau, are described briefly. Twelve stations for obtaining photographs by cooperative observers were in operation in 1952 and 1953. No conclusive results are given, but comparison of photographs obtained in 1952 with the daily streamflow suggest favorable results.
Keywords: Photographic analysis of snowcover, Snowcover distribution

Snow survey data in the Water Resources Review - Eisenlohr, W.S. (21st Annual Western Snow Conference, 1953)
A plan is presented by the U.S. Geological Survey office at Washington D.C. to expand the distribution of the Water Supply Forecast volumes by publishing them in the April 1 issue of their nationally circulated WATER RESOURCES REVIEW. This publication and distribution would greatly enhance the reader volume of this information to a diversified number of readers.
Keywords: Data publication, Water supply forecasting

An approach to streamflow forecasting - Fulcher, M.K. (21st Annual Western Snow Conference, 1953)
A water supply forecast scheme is presented for the Colorado River above Grand Canyon. A statistical study of 9 tributary streams resulted in a decision to treat each tributary by itself and then route them by correlation procedures for a collective forecast at Grand Canyon. The Green River above Linwood is used as the pilot study. Data from 10 precipitation stations were weighed by the Thiessen method. These data were used as a soil priming factor from the preceding fall months. Snow survey data from 9 courses were used for April 1 forecasts. Fall and winter temperatures through March were used as a temperature factor. Multiple regression formula are solve with the 4 variables, resulting in a multiple correlation coefficient of 0.918.
Keywords: Statistical analysis, Water supply forecasting

Snow surveys in the northeast and uses of data - Harrington, A.W. (21st Annual Western Snow Conference, 1953)
A historical and progress report on snow survey activities in the Northeastern states is presented. The measurement of snow and snow water equivalent was done in upper New York state as early as 1834 by John b. Jervis, for the purpose of estimating possible water supplies for reservoirs that regulated water for the Chenango Barge Canal. He also established the first two streamgaging stations in the United States in 1835 on Eaton Brook and Madison Brook, however records are not continuous. Charles A. Mixer made some snow water equivalent measurements in 1900, but were not continued. Continuous records were stated in 1926 following the procedures outlined by Dr. J. E. Church, Jr. The growth of snow surveys in the Northeast States has been consistent over the passing years and the application of the data has increased steadily, similar to those in the Western states. No irrigation uses are reported, however, forecasting from snow surveys is common for power production, flood control and reservoir regulation.
Keywords: History of snow surveys

The use of aerial photographs of snow depth markers in water supply forecasting - Henderson, T.J. (21st Annual Western Snow Conference, 1953)
Snow depth markers are placed at inaccessible locations to obtain snow depth by aerial photographs and visual observations. This data is related information from an accessible snow course, at similar elevation, where depth, water content and density are available. The density is then used to obtain the water content at the MARKER station. Many marker stations can be read in a single flight and in a few hours. A minimum of cost and time is expended to obtain much more data. This information is used in water supply forecasting and in weather modification evaluation. Photographs depict the style of the markers and locations being used. Graphs indicate the comparison of both types of data from the same location.
Keywords: Aerial markers, Water supply forecasting, Weather modification methods

High Sierra snow ablation observations - Kehrlein, O.; Serr, E.; Tarble, R.D.; Wilson, W.T. (21st Annual Western Snow Conference, 1953)
Qualitative observations made during July 1951 from elevations of 9000 - 14,000 feet as well as instrumental measurements made on the crest of Mt. Whitney are discussed. Snow in an air-exposed pan melted about 1.7 inches in a 24 hour period and in situ about 1.0 inch per day, and never exceed 10% of the total ablation. Results of observations indicate that considerable water evaporates from melting snow, but that the vapor loss is predominantly from moist soil and water surfaces, rather than from the snow surface. In discussion Dr. J.E. Church submits a series of letters from qualified specialists on the subject of ABLATION of snow at high altitudes.
Keywords: Snow ablation

A historical record of the use of snow cover forecasts in the mid-Columbia area - Kramer, H.A. (21st Annual Western Snow Conference, 1953)
A report is presented showing the usefulness of snow survey forecasts in pre-planning or industrial operations in the mid-reaches of the Columbia River. Mention is made of the dangers of population crowding into the seldom used flood plain of the large rivers and the difficulties of saving life and property when occupants cannot see the potential dangers. Conditions existing before and after the 1948 flood are depicted. Examples of flood warnings are shown in the text and documented for date and time.
Keywords: Economics of snow surveys, Flood warning

Evidence of man-made climate change - Krick, I.P. (21st Annual Western Snow Conference, 1953)
Cloud seeding to produce additional snow water content in the snowpack of the Upper South Platte and Arkansas River Basins in Colorado is explained. Detailed meteorological and physics of cloud characteristics for cloud seeding are descried. Evaluation is based on statistical methods, using a 10 year period of snow surveys water content data prior to seeding and comparing the 3 years of seeding data of snow surveys conducted during this period. Claims are made that seeding increased the snowpack by 200% over the basic 10 years, while other basins to the south along the Rocky Mountains did not show this increase during the seeding of the last 3 years. Charts illustrate the 3 years of seeding operations and location of river basin target areas. In discussion Milton S. Sachs points out that good results are shown in increasing the snowpack by cloud seeding in the northwest along the Cascades and Rockies. He states that large scale operations are more affective and not so difficult to evaluate.
Keywords: Weather modification evaluation, Weather modification methods

Use of base flow in forecasting runoff during the non-flood season - McDonald, C.C. (21st Annual Western Snow Conference, 1953)
A study is presented of streamflow for the period July through September for the Salmon river at Whitebird, Idaho as related to 'Base Flow' on July first. 'Base Flow' is considered to be the flow of a river after the snowmelt flood has drained from the soil and ground water aquifers and the recession graph has started to flatten off. Base flow on July 1 and precipitation during the period account for 97% of the variance in runoff. It is possible to forecast the total runoff from July through September within limits of error normally acceptable in water supply forecasting by means of base flow alone. The approach to each river would, of course, be different, but the theory holds. Relationships are shown graphically with probability and frequency curves being exhibited together with tabulated data and formula development.
Keywords: Base flow, Water supply forecasting

Base flow as a parameter in forecasting April-June runoff - Nelson, M.W.; McDonald, C.C.; Barton, M. (21st Annual Western Snow Conference, 1953)
A preliminary analysis using base flow of the preceding fall as a parameter in forecasting snowmelt runoff during April - June period for major tributaries to the Columbia River is presented. Three separate forecasting formulas were developed for each stream; first, using water content with April - June flow; second, using April 1 water content and November 1 base flow with April - June flow; and third, adding April precipitation. Statistical parameters for the 12 equations are tabulated and discussed. Base flow was found to be highly significant. April precipitation is not significant especially when it must be estimated for the April first forecast. In basins of low elevation headwater precipitation carried more weight. Base flow proved to be an integrating factor of difficult to measure variables, evapotranspiration, soil moisture and groundwater storage.
Keywords: Base flow, Water supply forecasting

The use of precipitation and snow survey data in water supply forecasting - Polos, A.J. (21st Annual Western Snow Conference, 1953)
The use of precipitation measurements and snow survey data singly and in combinations for forecasting is discussed and applied to the North Fork Clearwater River in Idaho. An average error of 8.7% was obtained using precipitation data alone, and 4.6% when combined with snow survey data. Forecasts issued by the Weather Bureau in January, February and March will use only precipitation data but April and May forecasts will also utilize snow survey data where applicable.In discussion Mr. Clarence Pederson indicates his approval of the combination of variables in the formula. However, he warns against using a precipitation period that extends beyond the date of the forecast. Using estimated or average figures invariably leads to trouble. Also reliable accuracy checks cannot be made by inserting the values of the variables used in developing the formula. If every 3rd or 5th data is omitted, and then a reliability check is made using these omitted, the check will be much more significant.
Keywords: Water supply forecasting

Concept and characteristics of base flow in the Columbia River Basin - Simons, W.D. (21st Annual Western Snow Conference, 1953)
Potentialities of using the base flow depletion curves as a parameter in streamflow forecasting are presented, especially for predicting fall and winter flows. Five factors are listed that are related to fluctuations in streamflow. Procedures for separating the hydrograph into its component parts are shown, particularly the recession limb. Procedures for constructing the base flow depletion curve are illustrated.
Keywords: Base flow, Water supply forecasting

Reproduction of snowmelt floods in the Boise River - Summersett, J. (21st Annual Western Snow Conference, 1953)
A largely empirical method for rapidly reproducing floods is described. The basic factors considered are: areal extent and depth of snow cover, maximum daily air temperature, precipitation, losses and the unit hydrograph. A natural and a computed hydrograph are compared with good agreement.
Keywords: Snowmelt floods

A new program of coordinated Federal-State water supply forecasts - Work, R.A.; Polos, A.J. (21st Annual Western Snow Conference, 1953)
An attempt is made to coordinate the water supply forecasts of the Soil Conservation Service, the U.S. Weather Bureau, and the British Columbia Department of Lands and Forests, Division of Water Resources, and California Department of Water Resources. The plan being to compare forecasts of all agencies, before issuance, where data is prepared for the same gaging station and runoff period. The coordinated forecasts would then be released to operating and regulating and water users in general. Thus eliminating confusing statements and varying figures. Plans are also made for mutual cooperation on research to produce better and more reliable forecasts through joint membership of the Water Forecast Committees for the major river basins in the Western United States.
Keywords: Water supply forecast coordination

1952 Title, Contents, and Minutes (20th Annual Western Snow Conference, 1952)

The relationship of precipitation intensity to avalanche occurrence - Atwater, M.M. (20th Annual Western Snow Conference, 1952)
Avalanche hazard is always a result of a combination of factors that must be analyzed simultaneously. These factors are reviewed with emphasis placed on precipitation intensity (the number of inches of water content deposited per hour), and snow fall intensity (the number of inches of fresh sow deposited per hour). Other factors involved are old snow depth and surface condition, total snow depth, type of snow, density of snow, amount of settlement, temperature, wind direction, wind velocity and hours of duration, the amount of sluffing (small slides from the upper portion of the avalanche area). Instrumentation for continuous measurement of these factors is discussed. Several storms which caused avalanches of varying size are analyzed by text and shown graphically. A tabulation of recorded data is displayed.
Keywords: Avalanche research

Use of snow surveys in evaluating cloud-seeding operations - Beaumont, R.T.; Work, R.A.; Frost, W.T.; Barton, M. (20th Annual Western Snow Conference, 1952)
Methods using data from mountain snow survey courses to study the results of cloud seeding are presented. Cloud seeding, to increase the snowpack and produce more water for irrigation on watersheds of the Rogue River Valley, Oregon, occurred from November 1949 through March 1950, and from November 1950 through March 1951. The target area and the techniques used in cloud seeding are described. Snow course records maintained 9-19 years in the target area and in upwind surrounding areas were analyzed. Correlation coefficients were established and used to determine if the target area received proportionately more or less water equivalent as snow than the surrounding areas. Analysis shows that less water was stored in the snow in the target area during the 2-year period of cloud seeding than expected under natural conditions. Further studies are required to determine whether the relationships between snow courses and streamflow sere modified by seeding.
Keywords: Weather modification evaluation

Methods of evaluation of cloud seeding - Elliott, R.D. (20th Annual Western Snow Conference, 1952)
Cloud-seeding experiments are hard to evaluate because of difficulty in segregating artificially created effects of seeding from natural processes. Control areas in the immediate vicinity which, from previously established records, are not liable to produce abnormal precipitation, should be chosen. It becomes increasingly difficult to find a control area which is not influenced by another cloud-seeding operation conducted nearby.
Keywords: Weather modification evaluation

Short term forecasting of snowmelt runoff - Gartska, W.U.; Bertle, F.A.; Dunford, E.G. (20th Annual Western Snow Conference, 1952)
A day-to-day streamflow forecasting procedure is illustrated by using snowmelt factors and computing the next day's runoff, thus segregating from the hydrograph the contribution of one day's snowmelt. The heat sources for melting snow are largely solar radiation, reflected solar radiation, heat from warm air masses and latent heat of evaporation from condensation of water vapor. The snowmelt formula developed by Phillip Light is used to correlate the weather elements to snowmelt and streamflow. Daily flows are solved concurrently to synthesize the seasonal runoff hydrograph. Graphs illustrate the procedure.
Keywords: Heat exchange, Short term forecasting, Water supply forecasting

Forecasted temperatures and snow melt floods - Gay, .W. (20th Annual Western Snow Conference, 1952)
Correlations of temperatures with snow-melt runoff from a watershed during the spring floods are presented. The establishment of correlations are discussed by which temperatures for April, May, June, might be forecast from data available on April 1, with sufficient accuracy to estimate the form and sequence of snow-melt runoff. The Methods forming the basis for such forecasting are presented. A forecast for the flow of the Boise River in the spring of 1951 from 28-year temperature data of Idaho City is made using average 5-day values of daily maximum temperatures. A satisfactory correspondence between the forecasted and the actual hydrograph is evident.
Keywords: Runoff, Snowmelt, Snowmelt flood, Temperature factor

Some research problems in snow mechanics and thermodynamics - Gerdel, R.W. (20th Annual Western Snow Conference, 1952)
The causes for discrepancies in the presently reported values for physical constants of snow are discussed. Snow strength is influenced by present and past temperatures and the frequency of temperature cycles. Some problems in snow mechanics are analogous to those in soils, but snow, particularly near the freezing point, may react oppositely for a given force. Releasing pressure on a soil increases its plasticity; releasing pressure on snow, near the ice point reduces plasticity by causing free water between the grains to freeze. The derivation of a traction index from the mechanical properties of snow or the forecastable degree of metamorphism is complicated by the inconsistency of the frictional resistance of the snow surface. Theories based on the narrow temperature range which separates the liquid, vapor, and solid phases of snow to account for the low but variable coefficient of friction for snow are discussed.
Keywords: Mechanical properties of snow, Snow research

Estimating precipitation at San Francisco from concurrent meteorological variables - Jorgensen, D.L. (20th Annual Western Snow Conference, 1952)
A study of meteorological factors responsible for producing rainfall is presented, and especially designed to develop a procedure for evaluating weather modification by the use of silver iodide generators. The main objective being to determine if rainfall would have occurred from a given set of atmospherical conditions without cloud seeding and if so, how much more was due to the artificial triggering. Upper-air masses at 400 and 700 mb. With open and closed low storm centers are plotted on scatter diagrams. Results are computed by probability theories and amounts of rainfall are snow. These data are compared to 12 and 24 hour amounts and monthly totals were computed by observed data.In discussion Dr. J. Neyman confines his remarks to the statistical probabilities and the procedures used in the paper and states that advance work will be forthcoming.
Keywords: Evaluation of weather modification, Methods of weather modification, Weather modification

The mission of the Snow, Ice and Permafrost Research Establishment - Lahlum, A.H. (20th Annual Western Snow Conference, 1952)
SIPRE conducts basic and applied research on the properties of snow, ice and seasonally or permanently frozen ground; studies the relations of snow, ice and permafrost to the environment; collects and disseminates information on snow, ice and permafrost to all elements of the Department of Defense; coordinates research undertaken by the Armed Forces, and others in the fields of snow, ice and permafrost to eliminate duplication.
Keywords: SIPRE, Snow research

The use of soot for snow removal purposes - Lang, W.A. (20th Annual Western Snow Conference, 1952)
Eight test plots, 10x10 feet, covered with 10 inches of snow, were evenly spread with soot varying from 0-10 pounds per plot. Snow depth and water content were measured with a sampler at the center of each plot before applying the soot and again 4 hours later. The temperature ranged from 22 deg to 47 deg F during the experimental period. The greatest decrease in snow depth occurred in the plot covered with 1 pound of soot. The rate of decrease in snow was almost twice as great on the sooted spots than on clear plots. No significant difference in the decrease of water content was found. Lampblack was applied experimentally on the Kaiser Pass road on March 30, 1951, at the rate of 10 pounds per 100 square feet as a method of snow clearance in spring. The danger of spreading the soot too thickly and preventing melting is pointed out in the discussion.In discussion Dr. Robert W. Gerdel points out some interesting references on the subject of 'Unconventional Methods of Snow Removal'
Keywords: Snow removal from roads, Snowcover radiation, Solar radiation

Soil priming in relation to snow surveys and flood regulation (Abstract only) See TAGU, 1952, 34:240-248 - Nelson, M.W.; Wilm, H.G.; Work, R.A. (20th Annual Western Snow Conference, 1952)
Earlier analyses of techniques for water forecasting in the Columbia River Basin found both water yields and food discharges to be highly correlated with the water content of snow as determined by snow surveys, and with spring precipitation. The present study demonstrates that the addition of preceding fall precipitation expresses the degree of soil priming and the extent to which autumn affect in soil moisture are replenished by precipitation before the snowpack accumulates each winter. The inclusion of the soil-priming variable, as compared to previous analyses, made a 40% improvement in the standard error of the forecast made on April 1 of each year. Similar improvements in precision were observed for later forecasts made on May 1 and May 15.
Keywords: Soil priming fall precipitation, Water supply forecasting

1951 Title, Contents, and Minutes (19th Annual Western Snow Conference, 1951)

Benefits of snow surveying - Clyde, G.D.; Houston, C.E. (19th Annual Western Snow Conference, 1951)
Several examples are used to show the benefits derived from the work being conducted by the Soil conservation service in the Federal-State-Private Cooperative snow surveys and irrigation water forecasting. Nearly 200 different organizations participate in the program through the contributed funds, labor or data. The method used by the Soil Conservation service to measure the water in the snow storage reservoir for establishing a relation between snow cover and runoff is explained. Typical benefits derived from the use of snow surveys and streamflow forecasts are cited, such as reservoirs operated for irrigation, hydroelectric power, flood control, recreation and other beneficial conservation uses are shown.Discussion by W.A. Lang, J.R. Riter, F.B. Blanchard and G.W. Templeton.
Keywords: Economics, Snow survey benefits, Snow survey economics

The Canadian snow-cover survey - Klein, G.J. (19th Annual Western Snow Conference, 1951)
The objective of the Canadian Snow Cover Survey was to obtain data on the physical features of the snow cover at a number of observation stations, and to provide a basis for future studies of the fundamental properties of snow. The method followed at each station consisted of digging a test pit in the snow cover once each week and measuring temperature, specific gravity, free-water content, hardness and average size and shape of snow grains. Air temperature, snow cover depth and the location of the snow layers were also determined. Standard snow classifications were used. Some of the results obtained show that air temperature and wind had a decided influence on the condition of the snow cover, while the effects of sunshine were small. The specific gravity of settled snow was usually between .25 to .35 and for wet settled snow the specific gravity rose as high as .65, at temperatures below freezing.Discussion by Dr. J.E. Church, Jr.
Keywords: Snow classification, Snow cover hardness, Snow crystals, Snow gages

Cumulative snowmelt runoff distribution graphs and their use in runoff forescasting - Koelzer, V.A. (19th Annual Western Snow Conference, 1951)
Procedures for refining total seasonal runoff forecasts as the snowmelt season progresses are presented on the basis of temperature and runoff data. Methods described were developed for operation in the Seminoe Reservoir in the North Platte River Basin, Wyoming. The principle of snowmelt runoff variations with changes in temperature is used to develop mass curves of accumulated values of day-degrees of melting temperatures against accumulated daily inflow to the reservoir. The mass curves have a striking similarity in shape. The possibility of comparing accumulated runoff expressed in percent of total seasonal runoff with accumulative day-degrees of melting temperature are investigated. Cumulative snowmelt runoff distribution graphs are developed. A definite relationship is found to exist between the percent of seasonal snow melt and cumulative temperatures.Discussion by Walter U. Garstka and Milton S. Sachs.
Keywords: Reservoir regulation, Runoff, Snowmelt, Water supply forecasting

Snowpack increase in the Colorado Rockies by artificial nucleation - Krick, I.P. (19th Annual Western Snow Conference, 1951)
Cloud seeding experiments to increase the snowpack were started in the upper watershed of the Arkansas River. Silver iodide generators located at ground level were used. Winter precipitation amounts of 10 western slope stations were correlated with upper Arkansas basin snowpack values. Results indicate that high precipitation and above normal snowpack years are usually associated with high ratio values of Aspen Precipitation to Arkansas water content. The water supply forecast based on snow survey data exceeds the forecast based on precipitation reports form valley stations.
Keywords: Water supply forecasting, Weather modification procedures

Localized effects induced by seeding supercooled clouds with dry ice and silver iodide - Schaefer, V.J. (19th Annual Western Snow Conference, 1951)
Condensation nuclei as condensation centers for the formation of cloud droplets. An automatic recording, condensation nuclei is used to detect the extreme variability in concentration of such nuclei. The seeding of clear air, supersaturated with respect to ice, with suitable nuclei causes the formation of ice crystals large enough to have a falling velocity within less than 1 minute after seeding. Various techniques of seeding stratus or cumulus clouds, using dry ice or silver iodide are described. Accounts of actual aerological seeding experiments made, and results obtained are indicated.
Keywords: Cloud Seeding, Silver Iodide, Weather Modification

Laboratory and field experiments with snow gages in Idaho - Warnick, C.C. (19th Annual Western Snow Conference, 1951)
A large slow-speed wind tunnel was constructed to study air movement around precipitation gages. The tunnel is made of plywood in sections which can be dismantled. Sawdust was used to illustrate air patterns and make quantitative evaluations of the catching characteristics of the gage. A Speed Graphic camera is mounted 25 inches above the floor of the tunnel in a small darkroom. The laboratory tests are centered around air flow phenomena near half-scale models of the gages and the catching characteristics of various gages equipped with different shields. Field studies, in progress for 3 winters, are in a plot containing 7 gages. Gage measurements are taken at weekly intervals by stick measurements. The tests in the tunnel indicate that the Alter Shield has the optimum basic shape. Field studies show a fault in the standpipe gages. The stored precipitation in the standpipe gage freezes and makes records questionable. (See also WSC 220-49: SIP U1807)
Keywords: Snow gage test results, Snow storm simulation, Wind tunnel

Some fundamental problems and investigational techniques in snowmelt forecasting - Wilson, W.T. (19th Annual Western Snow Conference, 1951)
An attempt is made to show how a program of investigations of snowmelt forecasting must be considered in the light of its economic and administrative involvement. The factors affecting snowmelt are discussed and procedures are suggested to be followed in developing forecast methods. It is emphasized that each drainage basin must be considered according to the physical conditions found on the drainage, even though considerable similarity between adjacent drainages might exist. It is pointed out that in addition to the very real problems of sampling variance and observational deficiencies, the theoretical elements that lend themselves to a rational solution are seldom observed in isolated fashion.Discussion by Wayne D. Criddle.
Keywords: Runoff, Snowmelt, Water supply forecasting

General requirements of a satisfactory over-snow machine - Work, R.A. (19th Annual Western Snow Conference, 1951)
A discussion of 13 basic characteristics, necessary for a universal proposed mechanized over-snow vehicle for use in snow surveys, is presented. A suggested relative numerical rating for each characteristic is included. These characteristics, in the order of importance, are: (1) mechanical dependability, (2) ability to travel on soft or sticky snow, (3) ability to traverse steep side slopes, (4) ability to operate on ground bare of snow, (5) ability to ascend steep grades, (6) maneuverability, (7) ability to quickly surmount obstacles such as fallen trees, (8) economy of operation, (9) speed, (10) ability to ford open flowing streams, (11) safety, (12) portability, and (13) comfort for 2 men.Discussion by George J. Klein.
Keywords: Oversnow vehicle development

Use of snow surveys in planning regulation of Columbia River floods - Work, R.A.; Wilm, H.G.; Nelson, M.W. (19th Annual Western Snow Conference, 1951)
A practical method for making predictions of volumetric yield and flood discharges from snow is presented. Available data on the water stored in snow in the spring and during subsequent precipitation are obtained from 43 selected snow courses. The predictions are accompanied by estimates of error and probable limits within which the real yield or flood discharge is likely to fall, by statistical means. Two-thirds of the total error in predicting peak discharges is in the error associated with the relations of flood volume to snow water. Later season forecasts become progressively more precise. The effects of early season temperatures on peak discharge were indirectly evaluated by subtracting April volume from the estimated April-June volume, and relating flood discharges only to the remaining amount expected to flow during the last part of the 3-month period.Discussion by Clarence Pederson.
Keywords: Statistical analysis, Water supply forecasting

1950 Title, Contents, and Minutes (18th Annual Western Snow Conference, 1950)

Snow safety - Atwater, M.M. (18th Annual Western Snow Conference, 1950)
A system of avalanche hazard forecasting was established in 1938 at Alta, Utah by the U.S. Forest Service, based on the snow research of the service. The objective was to provide snow rangers with a simple and logical method of forecasting critical avalanche hazard conditions and to develop protective measures. Hazard forecasting is a continuous process of observation of 10 avalanche factors, old snow depth and surface, new snow depth, type and density, rate of snowfall, wind force and direction, temperature developments and snow settlement. These factors are variables which operate singly and in combination, and may even have a simultaneous plus and minus effect. It is possible that some of the Alta techniques can be used by snow surveyors.
Keywords: Avalanche counter measures, Avalanche forecasting

Precipitation control - Barnes, C.S. (18th Annual Western Snow Conference, 1950)
The Precipitation Control Company of Phoenix, Arizona was formed to develop and perfect the mechanics and techniques of increasing precipitation. Silver iodide from airplane generators is used to seed super-cooled clouds. Calcium chloride is used to cause clouds to thicken and precipitate in non-super-cooled clouds. Ground generators have not proved successful. A technique called 'Advanced Air Mass Seeding' is used on days which appear to be favorable for cloud formation. Small clouds are seeded early in the day, preparing them for precipitation as soon a the clouds cool to the critical temperature. Two or 3 times as much rain is produced due to generation caused by reflected heat form the ground and rising air currents. Over-seeding in cloud structures is often brought about by smokes and vapors with subsequent loss of normal precipitation. The installation of precipitating and cleaning equipment in smoke stacks is recommended to increase the efficiency of seeding by silver iodide.
Keywords: Weather modification research

A day's contribution to the snowmelt hydrograph - Bertle, F.A.; Dunford, E.G. (18th Annual Western Snow Conference, 1950)
Recent work performed on the analysis of 1 day's contribution to the snowmelt hydrograph is summarized. The data are part of the Cooperative Snow Investigation of the USBR-USFS at Frasier Experiment Forest, and cover separately the St. Louis Creek and the Fool Creek drainage basins. The total runoff from each day's melt is defined and all measurements are correlated to the total volume of runoff from the one day's melt using the combined data from 1948 and 1949. The relationship of the first day's volume to the total volume is plotted. A definite break is apparent with the double mass curve of accumulated first day volumes vs. accumulated total daily runoff at the point representing the maximum runoff for the year. It is suggested that the 2 parts of the melt season, before and after the peak, be considered separately in establishing correlations.
Keywords: Runoff, Snowmelt, Statistical analysis

An industrial operation to produce precipitation - Cundiff, S.A. (18th Annual Western Snow Conference, 1950)
Cloud seeding (weather modification) experiments were carried out at Bishop Creek, California, during the winters of 1947-49. It was observed that clouds forming over the watershed were blown east and dispersed without precipitating. These clouds are usually deficient in nuclei and had temperatures between -10deg and -39deg C. Dry ice, distributed by airplane at the rate of 4 to 5 pounds per mile, was found to be superior to silver iodide. Precipitation occurred from 5 to 15 minutes after seeding. Over-seeding caused the dispersal of clouds. It was estimated that seeding operations increased the water yield by 14% in 1947-48 and 12% in 1948-49. The cost was approximately $200 per hour of seeding flight time, with flights ranging from 45 minutes to 1.5 hours. Approximately 50 flights were made in 1948-49.
Keywords: Weather modification procedures

The use of double mass analysis in testing the consistency of climatological records - Diamond, M. (18th Annual Western Snow Conference, 1950)
Double mass analysis was used to investigate the consistency of precipitation records in the Upper Colorado River basin. Residual mass curves, represented as the accumulated excess or deficiency of rainfall in relation to time, are plotted for each precipitation station's record. A horizontal curve indicates no major change in the average precipitation. Stations with nearly horizontal residual mass curves are used in preparing a precipitation base pattern. The precipitation record of a single station is plotted accumulatively against the accumulated precipitation base pattern. A straight double mass curve indicates a consistent precipitation record. A bend in the curve indicates that the records have been affected by artificial changes in exposure or observer. The results of the study indicate that double mass technique is reliable when there is a high correlation between factors being compared.
Keywords: Precipitation analysis, Statistical analysis

The use of radioisotopes in research on snow and runoff - Gerdel, R.W.; Mansfield, C.W. (18th Annual Western Snow Conference, 1950)
Three radioactive snow gages were installed in the experimental area at the Central Sierra Snow Laboratory, during December 1949. A geiger tube was held by a 20-ft. Truss arm attached to a 50-ft. Pole. A lead shielded collimator imbedded in concrete beneath the truss arm held 2 units of radioactive Cobalt 60. Impulses of the geiger tube were amplified and transmitted over a 150-foot Cable to the recorder in the main laboratory. Largest sources of error were in variation of background impulses caused by cosmic rays. Four of 7 -- 5 minute counting periods each day gave accuracy within 2 to 5%. Water films of less than 0.01 inch to 55 inches can be measured by means of beta emissions from Strontium 90, and gamma rays from Cobalt 60.
Keywords: Radioisotopes, Snow gage radioactive

Meteorological investigations of the effects of seeding clouds for increasing precipitation - Grant, L.O. (18th Annual Western Snow Conference, 1950)
Techniques for segregating the effects on precipitation of cloud seeding with dry ice and silver iodide are investigated. Weather records of Phoenix, Arizona for 1937-1947 were studied with respect to temperatures at different levels, stability of the atmosphere, winds, pressures at different levels, tropopause heights, and surface dewpoints. The weather records were compared with the result of seeding clouds during July 1948, Rain was observed after several of the seeding operations. Ground generators of silver iodide have given more consistent positive results than seeding by aeroplane.
Keywords: Weather research

Use of inflow forecasts in operation of Hoover Dam and Lake Mead for flood control - Lupton, F.R. (18th Annual Western Snow Conference, 1950)
A review of regulations for operating Hoover Dam to meet legal requirements is presented. Economical operation of the dam in conjunction with power and irrigation requirements and maintaining discharge releases to inhibit flooding below the dam are described. Maximum flow downstream from the dam is limited to 40,000 cfs which adds another restriction in releasing large volumes of flood control water. Storage space above the dam also has its control height to guard against use of spillways, thus a loss of power. Inflow volumes to the reservoir are forecast for each month January through July. The forecast scheme is designed for temperature and evaporation factors. Various months use different weighting of factors to meet the conditions. Accuracy is high in the first few months but improves considerably in the later months. Tables and graphs illustrate procedure explained in the text.Discussion by Gerald B. Levin.
Keywords: Reservoir regulation, Water supply forecasting

A revision of forecasting methods as practiced by the California Snow Surveys - Strauss, F.A. (18th Annual Western Snow Conference, 1950)
A revised procedure for forecasting runoff, basically a modification of the direct method of the California Cooperative Snow surveys, is presented. The snow water content, as measured by snow survey procedures, of the basin, adjusted to April 1 conditions is calculated as a percent of normal cover on that date. Corrections in this index figure are made for precipitation during the runoff period, for basin streamflow, for April temperatures at different snow courses and for soil priming. Streamflow forecasts, accurate within 10%, can be made from the corrected snowpack index.
Keywords: Water supply forecasting

1949 Title, Contents, and Minutes (17th Annual Western Snow Conference, 1949)

The economic aspects of snow - Burdick, R.T. (17th Annual Western Snow Conference, 1949)
Irrigation in many areas depends largely on water stored in the form of snow. The average precipitation during May to August at Montrose, Colorado is 37% during which period the flow in the Gunnison River is 67.4%. The delay of nearly 33% of the streamflow is attributed to snow accumulation. The result of experimental timber cutting at the Rocky Mountain Forest & Range Experiment Station at Fort Collins indicate that moisture stored can be increased approximately 25% by planned cutting on dense, high altitude forest lands. The Forest Service anticipates that timber cutting experiments may change the early snow melt and increase the streamflow through fall. Snow is an important economic consideration in the generation of power by streams.
Keywords: Economics, Runoff, Snowmelt

Science and adventure - Church, J.E. (17th Annual Western Snow Conference, 1949)
An autobiography relating to Dr. J.E. Church's scientific and humanitarian accomplishments in the field of ice and snow from 1895 through 1949. His foundation of the Mt. Rose Observatory in 1906 and early concepts of a relation to conservation of snowmelt and runoff to forest type and methods of timber cutting. The first authentic water supply forecasts of the rise in Lake Tahoe in 1910-1911, and listing of six elementary steps as an outline for forecasting procedures. Glacier ice melt does not add materially to the annual streamflow, only the snow melt on top of the glacier. Snow fall, ice and temperature measurements on the Greenland ice cap; snow survey conferences in Russia; snow surveys in India's Himalaya Mountains; snow surveys and water forecasting in the Andes of Argentina and Chile are discussed. International friendship in science overpowers political intrigue. Snow surveys and water supply forecast schemes for the Rhine and Rhone rivers with headwaters in Switzerland are of interest to Holland.
Keywords: Autobiography, Church, J.E.

Frazil and anchor ice - Farrow, R.C. (17th Annual Western Snow Conference, 1949)
Frazil ice is formed in turbulent streams when temperatures are below freezing.. Needles of ice from on the surface and are submerged by the turbulent water forming a turbid mass of ice and water. Slush ice is caused by heavy snowfall on open water that is near or below freezing point. Slush ice chokes intakes, penstocks and turbines, necessitating the closing of power facilities to clear the pipes. Experiments with steam to combat ice at intakes have proven expensive and inefficient. Compressed air forced through the water at the intakes has been effective. Anchor ice forms most rapidly on dark colored streambeds of turbulent streams on cold clear nights. Anchor ice never forms under the cover of sheet ice. Anchor ice will thaw loose and float away during days of bright sunshine and form again on very cold clear nights.Discussion by Ralph L. Parshall.
Keywords: Anchor ice, Frazil ice

Progress in snowmelt investigations at the Fraser Experimental Forest - Peasley, P.; Gartska, W.U.; B.C. Goodell (17th Annual Western Snow Conference, 1949)
The measurement of factors involved in the process of snowmelt as affecting quantity of runoff derived from melt over periods of daily, monthly, and seasonally are described. Five factors were selected for investigation.(1) The performance of shielded precipitation storage gages.(2) Methods of interpreting the commonly available daily maximum and minimum temperatures in terms of degree-days.(3) Analysis of rates of snowmelt.(4) Calculation of evaporation losses from snow.(5) Synthesis of rate of runoff from snowmelt hydrographs.Detailed data collected are shown on histographs and computations of snowmelt are illustrated in tabular form.
Keywords: Precipitation gage shielded, Runoff, Snow evaporation, Snowmelt

Technical progress in the cooperative snow investigations - Rhodes, F.L.; Wilson, W.T. (17th Annual Western Snow Conference, 1949)
The report of Mr. Rhodes and Mr. Wilson was a general discussion of this work of the Cooperative Snow Investigation Program being conducted by the Corps of Army Engineers and the U. S. Weather Bureau.A summary report of the Snow Investigations was prepared by the North Pacific Division of the Corps of Engineers, U. S. Army, Portland , Oregon, dated 30 June 1946, Titled Snow Hydrology.
Keywords: Cooperative snow investigations, Snow hydrology

Snow problems on Colorado highways - Stewart, D.N. (17th Annual Western Snow Conference, 1949)
The Colorado State Highway Department maintains 4000 miles of roads. The altitudes of these roads vary from 3,400 to 11,992 feet. Yearly snowfall averages range form 15.4 in. To 389.4 inches. The basic snow removal equipment consists of 217 heavy 4-wheel drive trucks equipped with reversible blade plows, 19 light trucks for light snowfalls, 18 heavy tractors to open high drifts, 16 rotary plows, and 19 rotary wideners for widening snow paths and removing packed snow from road edges. Light trucks are used for spreading abrasives on slippery roads. The cost of snow removal in 1947 was $426,000. Details are described of assignment of men and equipment and rotations of long hours.
Keywords: Snow removal equipment, Snow removal from roads

Studies on shielded snow gages - Warnich, C.C. (17th Annual Western Snow Conference, 1949)
Cooperative research was conducted by the University of Idaho, the Bureau of Reclamation, and other agencies to improve high altitude precipitation gages and their windshields. A smoke wind tunnel was built at the University of Idaho to study the action of wind around gages. A ventilating fan produced wind velocities of 20 Mi./hr. and smoke was generated by forcing dry air through a bottle of TiCl4 and combining the vapor with moist air. One-quarter scale models of Sacramento-type and Standpipe-type gages with and without shields were placed before the approach section to study the path of the airstream. Field studies were started September 1948 near Mullen Pass on the Idaho-Montana border. Two standpipe gages, two Sacramento storage gages and one Stevens-type Q12 recording winter-precipitation gage, equipped with various shields are being used. Results are as yet inconclusive.Discussion by J.C. Stevens.
Keywords: Research, Snow gages, Snow storm simulation

1948 Title, Contents, and Minutes (16th Annual Western Snow Conference, 1948)

the problem of snow in determining the spillway design flood - Barnes, B.S. (16th Annual Western Snow Conference, 1948)
Hydrographs from rain and from snow are combined to produce the design-flood hydrograph which is essential in determining the required capacity of the spillway of a dam. The rain flood is derived from a hypothetical storm in the basin. The snow hydrograph was derived by plotting the cumulative values of degree-days against cfs days in the form of a double mass curve. A lag of 3 days between temperature and runoff produce the smoothest curve. Runoff periods beginning and ending with the same temperature were selected, and the average slope of the mass curve for each period was determined. A degree-day factor was computed from the slopes. The degree-day factor was applied to a sequence of assumed temperatures to calculate the design snow-flood. The procedure is considered preliminary.
Keywords: Snowmelt and runoff, Spillway design floods, Statistical analysis

Hydrometeorological log of the Upper Columbia Snow Laboratory - Bertle, F.A. (16th Annual Western Snow Conference, 1948)
A summary of the hydrometeorological data gathered at the Upper Columbia Snow Laboratory during 1945-46 is presented. The Laboratory is located in the Rocky Mountains at Marias Pass, Montana, west of the Continental Divide. The field installations include 6 snow courses, 5 meteorological stations, 11 precipitation stations, and a streamflow measurement station. The tables, maps, and graphs present the data on radiation and reflection, temperature, degree-hours, wind, precipitation, snow depth and water equivalent, areal distribution of snow cover, streamflow, hydrological balance and various diurnal fluctuations. It was estimated that 19.7 inches of 38.5 inches of precipitation ran off in the streams. The remaining inches of precipitation are ascribed to loss by evaporation, ground water storage, underground seepage, and sampling error. Reflection of albedo amounted to 34 % of the radiation received.
Keywords: Cooperative snow investigations, Snowmelt runoff, Statistical analysis

Sequencein variation of annual precipitationin the Western United States - Clawson, M. (16th Annual Western Snow Conference, 1948)
Precipitation data from 211 weather stations in 17 western states from 1900-1939 were collected. Annual and cumulative deviations from long term averages were calculated. The sum of the cumulative deviations was divided by the sum of the annual deviations to obtain a coefficient which is a measure of the tendency for wet and dry years to occur in sequence. A coefficient equal to one fourth the number of years denotes a regular symmetrical cycle. The results show a tendency toward cycles of dry and wet years in the northern one-third of the western states. The results are suggestive rather than conclusive.
Keywords: Precipitation statistical analysis

Areal distribution of snow cover in relation to weather and terrain at Upper Columbia Snow Laboratory - Daniels, G.E. (16th Annual Western Snow Conference, 1948)
A preliminary examination of the topographical features, vegetation cover, and snow cover of the Skyland Creek basin of the Upper Columbia Snow Laboratory was made by the use of vertical aerial photographs which were sampled by a series of points. These points were defined by a rectangular grid of 420 intersections within the basin. From the data thus obtained a statistical study of the effects of topography and vegetation on the snow cover and snow melting has been made.Discussion by Joseph B. Paulson.
Keywords: Photographic analysis, Snow cover, Statistical analysis

Forecast flood-seasonal runoff - Ford, Perry M. (16th Annual Western Snow Conference, 1948)
A chart for forecasting the April-June discharge of the Swan River of the Flathead River Basin in Montana was prepared after statistical treatment of variables. The principal variables used were seasonal distribution of precipitation during the accumulation period and mean temmperatures during December and March. The chart involves precipitation weighted as to time of fall and the mean temperatures of December and March The chart is designed to forecast only the total April-June discharge of the Swan River.Discussion by Joseph Kittredge.
Keywords: Runoff, Snowmelt, Statistical analysis

The storage and transmission of liquid water in the snowpack as indicated by dyes - Gerdel, R.W. (16th Annual Western Snow Conference, 1948)
Fuchsine dye of the Fine-Y crystal type was applied to the surface of a shaded, spring snowpack at 0930 hrs. on May 15, 1947, near Donner Summit, California. The dye salt was uniformly applied to a 6x10 inch surface of a 30 inch pack. The free water content before the application of the dye was 1.5 and 2.6%. A pit was dug at 1200 hrs. To expose the vertical surface of the snowpack. In 2 hrs. 45 min., meltwater moved through the pack, 3 ft. Horizontally and 2 ft. Vertically. The horizontal movement was mainly along one major plane, and to a lesser extent along 8 definable planes. Movement was more uniform through coarse-crystal strata. Impounded water above semi-permeable crusts was found to be temporary. Indications are that liquid water will drain from the snowpack of 20 to 40% density and 4 to 6 ft. depth within 2 to 6 hrs. after melting ceases.Discussion by Ashton R. Codd with references and quotations from Dr. J. E. Church.
Keywords: Cooperative snow investigations, Snowcover permeability

Some observations on fall soil moisture under forest cover and their relations to the winter snowpack - Goodell, B.C. (16th Annual Western Snow Conference, 1948)
Extensive measurements of fall deficits in soil moisture were conducted in the Fraser Experimental forest. Soil samples were taken in an area of virgin lodgepole pine in late September, and again in the spring to determine the field-capacity of the soil. The difference between the average field-moisture capacity and the average fall-moisture content was the soil-moisture deficit. Soil moisture deficit averaged about 16% of the gross snow cover. Studies in Spruce and Fir forest cover showed about 14% deficits. Studies in a young lodgepole stand showed a deficit of 75% over a 2 year period.Discussion by H.L. Potts.
Keywords: Runoff, Snowmelt, Soil moisture measurement

Variation in depth of precipitation and in water equivalent of snow on the ground - Himmel, J.M. (16th Annual Western Snow Conference, 1948)
Tables and scatter diagrams are presented which illustrate variations in precipitation and snow measurements and derived relationships. The computed statistics give measures of these variations. A comparison of daily accumulations of precipitation and snow water equivalent values are discussed and illustrated. A comparison of accumulations of precipitation values from two separated gages and snow survey water equivalent increments for identical periods are also discussed and illustrated. Discussion by Harold A. Keith.
Keywords: Precipitation analysis, Snow water equivalent, Statistical analysis

Adjusting snow runoff correlation curves by use of autumn precipitation - MacLean, D.A. (16th Annual Western Snow Conference, 1948)
Stream runoff from snow is affected by the moisture content of the soil beneath the snow cover. Soil moisture condition is largely determined by precipitation during the autumn, months before the snowpack accumulates. Records of precipitation for August, September and October for 7 years at the Birchbank area of the Columbia River Basin were averaged and the departure from average was obtained for each year. Departure from average was multiplied by 1.5 and these corrections were added to or subtracted from the snow water content of the basin on each April 1. A graph of corrected snow water content against total streamflow showed closer correlation than when using uncorrected water content. Similar corrections for streamflow in other areas using factors of 0.5 and 3.0 show similar improvements in correlation.
Keywords: Runoff, Snowmelt, Statistical analysis, Water supply forecasting

The problem of an expanding ice sheet - Monfore, G.E.; Taylor, F.W. (16th Annual Western Snow Conference, 1948)
The coefficient of expansion of ice is about 30 X 10-6 per FO, or nearly 5 times that of steel, the Bureau of Reclamation made a study of the pressure exerted by an ice sheet during a rise in temperature. Two types of pressure gages were developed. The indentor gage consists of 2 circular sheets of steel held 0.625 inches apart by a steel ring. A hardened steel ball attached to the inside of one plate presses against a polished steel target on the other. Maximum pressure is measured by the amount of indentation. The resistance gage of similar shape can measure continuous pressure by change of resistance of a constantan wire on which a stretching force is applied during pressure. Laboratory experiments have yielded graphs for pressure exerted at various rates of increasing temperature. Two differential equations describing the thermal behavior of ice sheets were solved and the results plotted in a series of curves. Rate of change by mean temperature of an ice sheet can be obtained by multiplication of values read from these graphs. Field measurements have been started but definite results have not yet been reported.
Keywords: Ice pressure measurement