949 
fxus66 kmtr 240019 
afdmtr 


Area forecast discussion 
National Weather Service San Francisco Bay area California 
515 PM PDT Wednesday Jul 23 2008 


Discussion...as of 2:35 PM PDT Wednesday...other than some low 
clouds along the coast skies are mostly clear but smokey. Temperatures 
this afternoon are mainly in the 60s along the coast to the lower 90s 
inland. The feet Ord profiler indicate that the marine layer is near 1200 
feet. The gradient picture shows a robust 6.3 mb northerly gradient 
between Arcata-sfo and a moderate 2.0 mb onshore gradient between 
sfo-SAC. This combination has bought some weak downslope winds to 
the interior north and East Bay valleys where temperatures are as much as 
9 degrees warmer than yesterday. 


Models are in general agreement in building a ridge west into 
Southern California from the desert SW and southern rockies into the 
weekend. The NAM keeps the boundary layer dry so little in the way of 
low clouds/fog is expected. The district will be in the northern edge 
of the ridge with 500 mb heights near 591 dm and 850 mb temperatures between 
24-28c. This will bring warm weather to the district with above 
normal temperatures. However...latest model runs do not indicate any extreme 
heat...but 90s will be common in the inland valleys. The coast will 
remain in the 60s with the lack of an offshore flow and ocean water 
temperatures around 50. 


The ridge will begin to weaken slowly on Sunday with a trough 
approaching the coast early next week. This should cool temperatures down a 
little along with a return of the coastal low clouds and fog. With 
this pattern all monsoonal moisture will remain well to the south 
and east of the district. 


&& 


Aviation discussion...as of 5:15 PM Wednesday...clear skies will 
prevail across the region this evening with the exception of some 
smoke from the fires burning in the vicinity. VFR conditions expected 
at all terminal this evening with the exception of ksts that will 
experience some decrease in the visibility due to smoke. Temporary 
ceilings anticipated over Bay area terminals during the early morning 
hours Thursday...otherwise mainly clear. Ksjc will remain clear 
through the forecast period. Ceilings will return to the Monterey 
Bay area around midnight tonight. Clearing for kmry and ksns is 
anticipated around 17z Thursday. 


&& 


Mtr watches/warnings/advisories... 
... Arena to pt Piedras Blancas and sfo Bay. 


$$ 


Public forecast: mhs 
aviation/marine: c walbrun 


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