ARS | Publication request: EARLY FORECASTS OF SNOWMELT RUNOFF USING SNOTEL DATA IN THE UPPER RIO GRANDE BASIN

Submitted to: American Geophysical Union
Publication Type: Abstract Only
Publication Acceptance Date: November 19, 2002
Publication Date: December 6, 2002
Citation: DEWALLE, D.R., EISMEIER, J.A., RANGO, A. EARLY FORECASTS OF SNOWMELT RUNOFF USING SNOTEL DATA IN THE UPPER RIO GRANDE BASIN. FALL MEETING OF THE AMERICAN GEOPHYSICAL UNION. 2002. V. 83(47) P. F540.

Technical Abstract: In order to improve early forecasts of water availability from the Upper Rio Grande Basin in Colorado, we studied the accuracy of 1- to 6-month advance forecasts of snowmelt runoff based upon SNOTEL data. Equations were developed to forecast seasonal runoff volume, peak daily flow rate, and date of peak flow at the Del Norte, CO, streamflow gage using snowpack water equivalent measured at 7 SNOTEL sites during 1983-2001. Separate equations were developed for prediction on November 1 to April 1 prior to the melt season. SNOTEL data from only one or two sites were found to be significant in each monthly equation. Accuracy of forecasts was greatest for snowmelt runoff volumes, intermediate for peak daily flow rates and lowest for date of peak flow. Advance forecasts of runoff volumes based upon November 1 through January 1 data were the most accurate in a given year as frequently as February 1 to April 1 advance forecasts. While forecast accuracy generally increased from November 1 to April 1 overall, 55-75% of the variation in runoff volumes could still be explained with SNOTEL data 3 to 6 months prior to melt initiation. Snowmelt runoff volumes forecasted for 2002, the record low snowfall year, decreased each month from November 1 to April 1.