Scientific Forecaster Discussion
Area forecast discussion
National Weather Service San Francisco Bay area
440 am PDT Monday Mar 17 2014
Synopsis...a dry cold front will pass over northern California this
morning with some gusty winds and cooler temperatures for Monday
afternoon. High pressure this week will bring more dry weather
with temperatures generally in the middle 60s and 70s this week.
Discussion...as of 3:07 am PDT Monday...cold front has moved into
northern California with some light rain overnight up in Arcata and
Crescent City. Over the Bay area gusty onshore winds have developed
as the sfo-SAC gradient increased from flat to nearly 4 mb overnight.
Gusty west winds overnight at ksfo with gusts to 48 miles per hour last hour on
top of Mount Tamalpais. The winds and cool advection have been strong
enough to keep the boundary layer mixed and marine clouds are patchy
at best...so expect mostly sunny skies today but with noticeably cooler
temperatures especially for inland locations.
Skies will be mostly clear tonight into Tuesday morning with a very
dry airmass. This will allow some readings to fall into the middle and
upper 30s for wind protected valleys but not too concerned about any
frost potential given wind potential. A strong northerly surface
pressure gradient will set up overnight into Tuesday morning and winds
will be strong from the north/northeast up in the hills...keeping
overnight lows mild above 1000-1500 feet. Winds will ease after sunrise
and after a chilly start temperatures will warm well into the 60s and 70s
under Crystal blue skies for Tuesday afternoon.
The weather pattern remains quiet through the end of the work week.
Skies should be mostly sunny with minimal marine influence. Temperatures
will trend above normal with daytime highs from the middle 60s to middle 70s on
average. There may be a slight cooling trend by the weekend but in general
no changes of significance.
Models remain in good agreement with some type of rain chances by about
March 25/26. Even with the GFS/Gem and European model (ecmwf) all painting some type of
rain its still over one week away and we've seen several times this season
where the models back off on rain as the event nears. Will continue to
Aviation...as of 4:40 am PDT Monday...strong onshore and
increasing northerly gradient this morning ahead of a dry cold
front. Patchy ceilings 2000 to 3000 feet during next few hours at Bay
area terminals with frontal passage...likely becoming VFR by middle
to late morning. Moderate onshore winds this afternoon.
Vicinity of ksfo...patchy ceilings next few hours with frontal passage
then VFR. Medium confidence. Moderate west winds in the afternoon.
Ksfo bridge approach...similar to ksfo.
Monterey Bay area terminals...MVFR ceilings possible middle to late
morning with frontal passage...otherwise VFR.
... Surf advisory...along the coast until 8 am
Small Craft Advisory...pt pinos to pt Piedras Blancas 0-10 nm
Small Craft Advisory...pt pinos to pt Piedras Blancas 10-60 nm
Small Craft Advisory...pt Arena to pt Reyes 0-10 nm
Small Craft Advisory...pt Reyes to Pigeon pt 0-10 nm
Small Craft Advisory...Pigeon pt to pt pinos 0-10 nm
Small Craft Advisory...Pigeon pt to pt pinos 10-60 nm
Small Craft Advisory...pt Arena to pt Reyes 10-60 nm until 3 PM
Small Craft Advisory...pt Reyes to Pigeon pt 10-60 nm until 3 PM
glw...pt Arena to pt Reyes 10-60 nm from 3 PM
glw...pt Reyes to Pigeon pt 10-60 nm from 3 PM
Small Craft Advisory...rough bar advisory for sf bar until 3 am
Small Craft Advisory...Monterey Bay from 3 PM
Public forecast: rww
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