Fall is fast-approaching; fire weather concerns persist

Filed in Uncategorized by on September 14, 2007 9 Comments

The first significant storm system of the year will move into CA next week, bringing windy and cooler conditions but probably little or no rainfall. A rather deep low will become cut-off from the mean flow off of the West Coast, dropping south over CA by the end of next week. Major uncertainties still exist as to the low’s exact track, which have major implications for the weather that it produces. If the ECMWF verifies, the low would drop just inland (still west of a true “inside-slider” and produce cool weather, brezzy conditions, and possibly enough instability for a few showers or thunderstorms. The GFS brings the low offshore the SoCal coast, meaning that the flow over most of CA would become easterly or southeasterly. This could manage to draw up some mid-level moisture for some elevated convective activity, but mainly would serve to maintain warm temperatures, decrease humidities, and develop a pretty strong offshore wind event (in excess of 40 mph for much of the state). Obviously, this scenario would have serious fire weather implications, so stay tuned. Precipitation would be quite light in any case, and most places won’t see anything at all. The GFS has consistently been indicating an amplification of the pattern over the Eastern Pacific in the 2 week period, which is a good sign that the seasons are indeed changing. I still don’t expect any significant rainfall for most of CA for at least another month, though it does appear that La Nina may already be having some impact on the weather. 

 If you have not already done so, check out the recently-updated Seasonal Outlook at

http://www.weatherwest.com/outlook.html