HR: 10:50h
AN: GC32A-03    [Abstracts]
TI: Trends in Extreme Precipitation Events in the Western U.S. Since 1979
AU: * Wolter, K
EM: klaus.wolter@noaa.gov
AF: Climate Diagnostics Center, R/CDC1 325 Broadway, Boulder, CO 80305-3328 United States
AU: Eischeid, J K
EM: jon.k.eischeid@noaa.gov
AF: Climate Diagnostics Center, R/CDC1 325 Broadway, Boulder, CO 80305-3328 United States
AB: Several hundred automated SNOTEL sites have been established and maintained in the subalpine zones of the Western U.S. for more than two decades. Daily precipitation and snow water equivalent (SWE) data are two key measurement variables that are screened for extreme events, defined here as the highest precipitation totals and (positive) SWE changes over running five day (pentad) windows. From October 1978 through September 2003, the most extreme pentadal events are established for each water year, as well as for the full station record. Analogous computations are performed for conventional COOP climate stations in the Western U.S. Questions to be addressed include: 1. Are the most extreme pentadal events of each year increasing in size since 1979? If so, where? Are such trends statistically significant? 2. Are these extreme events at the SNOTEL sites the same as the corresponding events at adjacent COOP sites? How much can we trust COOP sites to monitor extreme events at higher elevations? 3. Is there a difference between trends in extreme rain (no SWE change) and snow events? 4. In the absence of strong trends, what is the role of ENSO? Does it fit previously established ENSO associations with U.S. precipitation?
DE: 1616 Climate variability (1635, 3305, 3309, 4215, 4513)
DE: 1637 Regional climate change
DE: 1817 Extreme events
DE: 3354 Precipitation (1854)
SC: Global Climate Change [GC]
MN: Fall Meeting 2005