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fxus66 ksgx 212122 
afdsgx 


Area forecast discussion 
National Weather Service San Diego California 
200 PM PST Sat Nov 21 2009 


Synopsis...residual moisture will continue patchy coastal low 
clouds tonight. Otherwise...mostly clear. Warmer through the middle 
of next week under high pressure with weak offshore flow. Cooler 
again by next weekend. 


&& 


Discussion...for southwest California including San Diego... 
Orange...southwest San Bernardino and West Riverside counties. 


Tonight through Monday...patchy low clouds west of the mountains 
through tonight with variable high cloudiness. Pressure gradients 
continue onshore but are trending weaker to the north...with about 4 
mb san-ipl and 5 mb san-las. 


The upper trough moving off to the east will leave behind a little 
low level moisture for patchy low clouds west of the mountains tonight 
and variable high cloudiness through Sunday. Dry northwest flow will 
continue through Sunday as a series of minor upper level troughs 
pass to the north. Surface pressure gradients will become weakly 
offshore to the north for a brief period tonight into Sunday 
morning...but remain onshore to the east. This will have little 
effect except to lower humidities a little in the northern areas. 
Clear and a little warmer on Sunday...then even warmer Monday under 
high pressure with weak offshore flow. 


Tuesday through Saturday...upper level ridging and weak offshore 
flow will continue through middle week. This will maintain generally 
clear skies with a warming trend. Thursday should be the warmest day 
in most areas with maximum temperatures about 5 to 10 degrees above seasonal 
averages in the inland valleys and foothills. There will be local 
gusty winds through and below mountain canyons and passes at times 
but they are expected to remain below advisory strength with most 
gusts less than 35 miles per hour. Cooler Friday and Saturday as a low pressure 
trough moves through to the north and onshore flow returns. 


&& 


Aviation... 
212000z...marine layer expected to drop tonight to about 1500 to 
2000 feet. Flow going offshore and forecast models are showing mostly 
clear tonight through Sunday. Will go for clear skies tonight 
through Sunday with possible visibility 3-5sm and isolated lower tonight. 
Expect any fog that develops will in the near coast areas with 
isolated brief dense fog possible Sunday morning. Otherwise...clear 
through Monday. 


&& 


Fire weather... 
no short term fire weather concerns. Next concern is still the 
prolonged offshore wind pattern for next week. This still looks like 
a weak to briefly moderate event. Adding forecast wind gusts and relative humidity 
values to the extended portion of each fire weather zone forecast in 
this afternoons. Numbers are similar to those mentioned in the 900 
am are forecast discussion. Looking further out...assuming the 
models are dead on accurate with the strength and position of the 
ridge...a much stronger offshore wind event is advertised to finish 
out the month of November. 


&& 


Sgx watches/warnings/advisories...none. 


&& 


$$ 


Public...pg 
aviation...Whitlow 
fire weather...Balfour