Rain-On-Snow on Donner Summit, California

TitleRain-On-Snow on Donner Summit, California
Publication TypeConference Proceedings
Year of Conference2019
AuthorsOsterhuber, Randall
Conference Name87th Annual Western Snow Conference
Conference LocationReno, NV
Keywordsflood, rain-on-snow, rainfall, snowpack outflow

Rain-on-snow events occur regularly during winter in the Donner Pass area of California, and their frequency is increasing. These storms have the potential to dramatically alter the stratigraphy of the snowpack, initiate rapid streamflow response, and cause local and downstream flooding. This paper reviews rain-on-snow events on Donner Summit, California at 2098 m elevation. Examined are case studies, rain-on-snow event size, duration, frequency, timing, anecdotal field observations, and supporting hydrometeorological data and snowpack response. Since the mid-1970s, personnel at the UC Berkeley Central Sierra Snow Laboratory have collected detailed information on precipitation type, highlighting the frequency and increasing trend of liquid precipitation during the (historic) snow season.