HR: 1340h
AN: GC33A-1245    [Abstracts]
TI: The Documentation of Extreme Hydrometeorlogical Events: Two Case Studies in Utah, Water Year 2005.
AU: Bardsley, T
EM: timothy.bardsley@ut.usda.gov
AF: NRCS Snow Survey, 245 N. Jimmy Doolitte Rd., Salt Lake City, UT 84116 United States
AU: Losleben, M
EM: Mark.Losleben@colorado.edu
AF: Mark Losleben, 818 County Road 116, Nederland, CO 80466 United States
AU: * Julander, R
EM: randall.julander@ut.usda.gov
AF: NRCS Snow Survey, 245 N. Jimmy Doolitte Rd., Salt Lake City, UT 84116 United States
AB: The Natural Resources Conservation Service, formerly the Soil Conservation Service, has monitored mountain snowpack and precipitation in the Western United States since 1934. The automation of measurement sites began in the late 1970s and now over 700 snow telemetry (SNOTEL) sites are installed, most reporting hourly. The established length of record and hourly records now make it possible to evaluate and document extreme hydrometeorlogical events. Two recent events brought the documentation of extreme events to the attention of the Utah Snow Survey office. During October 20 - 22, 2004, the twenty four hour precipitation intensities for six Utah sites exceeded the National Weather Service estimated 100 year average return interval, and eleven of seventy seven Utah sites with 15 years or longer record, measured the maximum twenty four hour precipitation intensity of record. A second event, Jan 8 - 12, 2005, ravaged SW Utah with high intensity rains and snow leading to the flooding of the Santa Clara River and the destruction of over twenty homes. This event is particularly relevant to the precipitation form issues of rain, snow, or rain-on-snow. This paper will evaluate the atmospheric circulation conditions that drove these events, and present precipitation intensities, absolute precipitation, snow water equivalent storm totals, and stream flows. The Utah NRCS Snow Survey office is working towards a Snow Survey system wide protocol for the documentation of extreme events recorded by SNOTEL stations that will provide validation and documentation of extreme events, easily accessed by current and future data users.
DE: 1620 Climate dynamics (0429, 3309)
DE: 1821 Floods
DE: 1840 Hydrometeorology
DE: 1863 Snow and ice (0736, 0738, 0776, 1827)
SC: Global Climate Change [GC]
MN: Fall Meeting 2005