Hydrologic response of central Sierra Nevada snowpacks to rainfall

TitleHydrologic response of central Sierra Nevada snowpacks to rainfall
Publication TypeConference Proceedings
Year of Conference1983
AuthorsBergman, J. A.
Conference Name51st Annual Western Snow Conference
Series TitleProceedings of the 51st Annual Western Snow Conference
Date PublishedApril 1983
PublisherWestern Snow Conference
Conference LocationVancouver, Washington
KeywordsRain-on-snow, Sierra Nevada snow zone, Snow hydrology

Seven natural rain-on-snow events of more than 4.5 cm were studied at the Forest Service's Central Sierra Snow Laboratory near Soda Springs, in the Sierra Nevada of California, to determine if a pattern of snowpack response exists. All or part of the snowpack was below freezing beforehand but warmed to almost 0 degrees C by the time rain ceased. The typical response was a decrease in overall snow depth, and increase in average density, no change or a slight decrease in snow water equivalent, and only a small increase in runoff due to rain-caused melt. High density layers that increased substantially in density during a storm may have delayed downward flow and directed water laterally into existing drainage channels; this would refute the theory that rain water may percolate evenly through the snowpack with drainage occurring only after its storage potential is satisfied.