Application of snowcovered area to runoff forecasting in the southern Sierra Nevada

Long-term snowcovered area data from aircraft and satellite observation made it possible to analyze the effect of snowcovered area on water supply forecasting procedures in California's southern Sierra Nevada. Water supply forecasting procedures utilizing snowcovered area as a parameter were developed on the Kings River and Kern River under the sponsorship of the California Department of Water Resources and NASA. 1978 was the first season with major snowmelt runoff since the procedures were developed, and snowcovered area was used operationally in making and updating the forecast through the period of snowmelt runoff.The forecast procedures developed for the Kern River did show a substantial reduction in error as the season progressed. Results were far from dramatic on the Kings. During 1978 a series of storms throughout the winter with extremely high freezing levels produced snowpack in the order of 200 percent of normal at higher elevations. The relatively high snow lines and lighter snowpack at the lower elevations were not consistent with snowpack at upper elevations.