889 
fxus66 kmtr 200601 
afdmtr 


Area forecast discussion 
National Weather Service San Francisco Bay area California 
1100 PM PDT Tuesday Aug 19 2008 


Discussion...as of 7:45 PM PST Tuesday...a somewhat broken area of 
stratus that covered the coastal waters earlier today has now 
compressed into a narrower strip of stratus right along the immediate 
coast. A few breaks in the clouds are noted near Monterey Bay. East 
and west of this narrow cloud band skies are mostly clear indicating 
subsidence. The wind flow pattern at 925 mb indicates a weak low 
level trough is present near the coast which appears to be shaping 
the stratus into its present formation. 925 mb humidities are 
forecast to decrease over the coastal waters and landmass tonight but 
nocturnal cooling favors less to no mixing so the probability of 
coastal stratus sticking around for the night is moderate to high. 
Surface dewpoints have popped up a little in the last 24 hours and 
this supports stratus. Boundary layer forecast trends from the NAM 
show stratus as well. Present wording in the zone forecasts look 
good. 


Temperatures today were near normal for the most part. Highs were in 
the middle 60s right at the coast to the low 80s like in Gilroy and King 
City. Normal to slightly above normal temperatures are forecast 
through the week. 


The GFS/European model (ecmwf) still hint at the possibility of The Four Corners high 
expanding westward into norcal this weekend. However the latest model 
runs appear weaker with this solution compared to yesterday. In the 
interim expect the westerlies to remain in place with a firm footing. 
Expect usual Summer-time weather with some night and morning coastal 
low clouds and fog with clear skies inland. 


No updates are expected tonight. 


&& 


Aviation...as of 11:00 PM PDT Tuesday...areas of stratus persist 
along the central coast tonight with patches of stratus over inland 
areas. Inland status appear to be dissipating resulting in ceilings 
moving in an out of some terminals. This will continue for the next 
few hours before ceilings establish themselves later tonight. 
Ceilings will scatter out between 17z-19z with coastal terminals 
clearing out a bit later. 


&& 


Mtr watches/warnings/advisories... 
... Pinos to pt Piedras Blancas to 20 nm and 
sfo Bay. 


$$ 


Public forecast: canepa 
aviation/marine: c walbrun 


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