Quantifying lake effect precipitation in the Great Salt Lake Basin

The Great Salt Lake Basin of the Intermountain West is one of the fastest growing regions of the United States. Consistent with the rapid population growth is the increased need for water resources, which are limited in the arid West. Since most of the water resources in the Great Salt Lake Basin come from precipitation and related runoff, it is essential to understand and quantify the sources of precipitation in order to plan for future water usage. Lake effect storms initiated over the Great Salt Lake are often overlooked in this regard, but are suspected to contribute significantly to overall precipitation amounts. Many studies have been conducted on the synoptic and mesoscale processes associated with Great Salt Lake Effect, but none have tried to quantify the amount of precipitation produced. This study examines the relationship between the Great Salt Lake Effect and the hydro-climate of the Great Salt Lake Basin by resolving the contribution of lake effect precipitation to annual precipitation. Imagery from the WSR-88D radar at Promontory Point (KMTX) is used to identify all lake effect events occurring from September 1997 to April 2010, noting the spatial extent, strength, and brevity of each storm. KMTX Radar and surface observations from SNOTEL, NWS, and cooperative observing stations are used to estimate precipitation amounts from each lake effect event. This approach is expected to yield a more objective estimate of the contribution of lake effect precipitation to annual precipitation.