Weather

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Area forecast discussion 
National Weather Service San Diego California 
845 PM PST Monday Jan 5 2009 


Synopsis... 
slow warming through midweek under weak high pressure. A trough of 
low pressure will bring cooling for Friday into Saturday...followed 
by moderate to strong offshore flow and warming for the weekend 
through early next week. No significant precipitation is expected 
through next week. 


&& 


Discussion...for extreme southwestern California including Orange... 
San Diego...western Riverside and southwestern San Bernardino 
counties... 


Surface pressure gradients have turned onshore this evening. 
Apparent weak eddy over the bight has helped to generate areas of 
lower marine clouds west of the mountains satellite imagery shows 
considerable high and middle level clouds moving S over the region. 
This will make it difficult to see development and extent of the 
lower marine clouds. The clouds will help to moderate temperatures 
overnight. Locally gusty winds to 35 miles per hour have been reported this 
evening at several mountain locations with a 45 miles per hour gust reported at 
Julian. 


Weak shortwave diving south over California this evening difficult to 
identify in satellite imagery...but has been generating light 
showers farther up the coast. Models move it through quickly...so 
the strongest winds and the threat of any sprinkles will decrease 
after midnight. Any clouds that linger into tomorrow morning should 
be short-lived. Behind this system heights/thickness gradually build 
into early Thursday bringing warmer days. 


The next shortwave looks to be better defined...but will be moisture 
starved...so any rain that may develop would probably not be 
measurable. Onshore flow and cooling will precede the wave Thursday 
afternoon into Friday...followed by offshore flow over the weekend. 
Sat will likely be cool and dry with better warming on sun and Monday. 


Other than sprinkles or patchy drizzle on Friday...the chance of 
getting any measurable precipitation will be minimal through at 
least the middle of next week as a massive upper-level high develops 
over the east Pacific...pushing the polar jet stream far to the north. 


Enjoy what meager moisture we have in the air for the next few days 
because once the offshore flow starts Sat...it will be very dry well 
into next week. 


&& 


Aviation... 
060440z...areas of stratus with bases around 2000-2500 feet mean sea level will 
occur in the coastal and valley areas through 17z Tuesday. Stratus will 
be most prevalent in San Diego County. Most visible will stay above 5 
miles. Locally gusty west-northwest winds will occur over the 
mountains...especially the crests/passes/desert slopes...through about 
09z with local surface gusts over 30 knots and low level wind shear. Otherwise...mid-level 
cloudiness will continue through midday Tuesday...mostly in the 
7000-12000 feet mean sea level layer. Clear skies will occur late Tuesday and Tuesday 
night. 


&& 


Sgx watches/warnings/advisories... 
California...none. 
Pz...none. 


&& 


$$ 


Public...jad 
aviation/marine...Maxwell 


National Weather Service on the web at weather.Gov/sandiego