Extended Abstract (604K)12.1
A preliminary survey of costly past weather events in southern California and a look at other potentially costly weather events
Ivory J. Small, NOAA/NWS, San Diego, CA
Southern California weather is often thought of as being “benign”. This is mainly because the majority of people in southern California reside near the coast, which is also where most of the tourists visit. Many people are unaware that the National Weather Service Forecast Office in San Diego has one of the most geographically diverse forecast areas in the National Weather Service, extending from sea level at the coast, to over 11,000 feet MSL in the mountains, then down to below sea level in the deserts. This setup results in a large variety of weather occurrences that do not affect the coastal strip, hence are not perceived as problems in the “San Diego Area”. For example, inland areas, (especially the foothills and lower mountain slopes) have weather that is vastly different than that of the coastal strip. Especially problematic is the late summer to mid winter period where there is a transition that goes from one very expensive weather problem to another in the lower mountains and foothills. This period can best be described as “it blow, glows, flows, and snows” (the Santa Ana winds blow, the resulting fire glows, early season rain and mud in the burned areas flows, and by mid winter, it snows).
In order to illustrate these events, flow patterns, moisture patterns, and thermal patterns will be investigated for the more costly weather events in the WFO San Diego Forecast area. The period of the weather events analyzed is from 1948 to 2005 as reported in storm data. It appears that leading the list of disastrous events is fire. For example, the total cost for the late October 2003 through early November 2003 firestorms was estimated to be in excess of 1 billion dollars. Standardized anomaly theory will also be applied to help show how “far from normal” the meteorological conditions for these events were. Some additional events with high potential for costly damage will also be presented. One of the goals of this paper is to show which types of patterns have (or could possibly) result in such costly, damaging events.
Session 12, Extreme Weather and Climate
Thursday, 24 January 2008, 1:30 PM-3:00 PM, 219
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