HR: 0800h
AN: GC11A-0130    [Abstracts]
TI: Potential Predictability of Summertime Rainfall Extremes Over the Southwestern US
AU: Wang, J
EM: wjy@bu.edu
AF: Department of Geography and Environment, Boston University, 675 Commonwealth Ave., Rm.457, Boston, MA 02215, United States
AU: * Anderson, B T
EM: brucea@bu.edu
AF: Department of Geography and Environment, Boston University, 675 Commonwealth Ave., Rm.457, Boston, MA 02215, United States
AU: Salvucci, G
EM: gdsalvuc@bu.edu
AF: Department of Geography and Environment, Boston University, 675 Commonwealth Ave., Rm.457, Boston, MA 02215, United States
AB: Many investigations of the North American monsoon system, particularly as it impacts northwestern Mexico and the southwestern United States, have focused upon summertime precipitation and its intraseasonal to interannual variations. While it is well known that in this region seasonal-mean rainfall anomalies and extreme- event occurrences - such as long-term drought and heavy rainfall events - have significant year-to-year variability, it is still unclear how much of the variability is actually due to climate-related shifts in the rainfall characteristics during anomalous years. Here we will show how stochastic models, in which the simulated interannual and intraseasonal rainfall variance is purely the result of the random evolution of daily rainfall events within a given year, can be used to identify and quantify those observed rainfall variations that are associated with systematic changes in the underlying rainfall characteristics and hence are "potentially predictable." This method can be used to isolate "hot spots" within the domain where potentially predictable signals occur more frequently than at others. In addition, though, the method can also be used to highlight potentially-predictable "hot events" at a given station or in a given region for use in analysis and model-evaluation studies. This presentation demonstrates how this technique has been used to: 1) identify summertime rainfall extremes over the southwestern US; and 2) analyze the large-scale and regional climate features related to these extremes.
DE: 1812 Drought
DE: 1817 Extreme events
DE: 1833 Hydroclimatology
DE: 3305 Climate change and variability (1616, 1635, 3309, 4215, 4513)
DE: 3354 Precipitation (1854)
SC: Global Environmental Change [GC]
MN: 2007 Fall Meeting