Key Words: Weather, Snowfall, Forecasting

In the wintermonths,Decemberthrough March, 1995-96a methodology was adapted and used forforecasting
snowfall amounts at the 9000 to 9500 foot elevation at the Jackson Hole Ski Area,located in the Teton Range in
the northwestern corner of the State of Wyoming. This method utilized easily obtainable atmospheric variables
fromsynopticscaleweathermapsand prognosticchartstoformulateaQuantitative Precipitation Forecast,(
QPF),forthefollowing24hourperiod.Atmosphericvariablesusedinthisstudywere:precipitable water,
temperature, upward vertical velocity and vorticity.Each of these factors were considered and weighted in the
formulation of the QPF, accordingto their relativesize and/or strength, as well as their expected duration Each of
these variables could be taken from available daily meteorological information and existing computer models of
the atmosphere, to calculatea daily QPF. The end goalis to develop a simple formula in a computer programthat,
after enteringattained values and answering a few questions, will estimate the amount of snowfall at a mountain
elevation. This method is not a complex computer model based on a specific topographicor geographic area, nor
is it based on any statistical orhistorical storm analysis.Thisis a best "guesstimate",if you will,of forecasted
snowfall based on current and forecasted meteorological variablesthat can be assigned a weight orvalue and
pluggedinto the formula. Calculation's of QPF's were verified each dayfor accuracy, on days when snowfall was
forecast and received, with an averagepercentageof accuracyusing this method of 80%for the entirewinter. This
only includes days which had snowfall in the forecast.Zero category days were not included in the accuracy
analysis. That is, days when no snowfall was forecast and no snowfall was received, were not counted as correct.
If zero category days are included the accuracy of this method increased to 87% forthe Winter of 1995/96.