NWS Forecast Area Discussion - San Francisco Area

FXUS66 KMTR 222034

Area Forecast Discussion
National Weather Service San Francisco Bay Area
134 PM PDT Mon Oct 22 2018

.SYNOPSIS...Slightly cooler temperatures are forecast across the
region through midweek as an upper level system pushes inland over
the Pacific Northwest and northern California. High pressure then
builds over the region late week and allows for temperatures to warm
to above seasonal averages. Dry weather conditions are also likely
to prevail through the forecast period.

&& of 01:32 PM PDT Monday...Morning low clouds were
slow to fully burn off this afternoon. Mostly sunny skies do
prevail for most locations, but the slow clearing kept
temperatures on the cooler side. Did make some minor adjustments
downward for max temps across the interior this afternoon.

Day to day sensible weather remains nearly the same in the short
term as night and morning low clouds continue. Daytime
temperatures will be close to seasonal averages with highs in the
60s and 70s. A few interior locations will likely eclipse 80
degrees. There is a weak disturbance sliding into far NorCal
Tuesday night into Wednesday. Latest guidance brings a small
chance for precip will be for the northern coastal waters. Even
better chance will actually be north of the Bay Area. One thing
the passing disturbance could do is disrupt the marine layer and
bring a few mid-high level clouds. Will keep forecast dry for the
time being.

High pressure and upper level ridge are forecast to build behind
the departing disturbance. ECMWF mos ensemble guidance brings a
noticeable warming trend Friday and Saturday. Synoptic set up even
suggests some offshore flow (not super strong) to the region.
Interesting to note the upper end of the ensemble envelop pushes a
few locations in the upper 80s /low 90s. Not totally sold on this
yet, but warmer is possible. Therefore, did bump a few high
temperatures on Friday and Saturday. The marine layer will likely
be a little more compressed during this timeframe.

Ridge flattens on Sunday with a slight cooldown and increased
onshore flow. Longer range continues to keep the Bay Area dry.

&& of 10:45 AM PDT Monday...for 18Z TAFs. Profiler
data and pilot reports indicate a fairly deep marine layer with
bases around 1000 feet and cloud tops around 2000 feet. Onshore
flow is in place and expect a fairly slow burn off through 19z for
most terminals. Expect stratus to spread back inland overnight
with similar synoptic pattern in place.

Vicinity of KSFO....Stratus forecast system and current trends
expect clearing shortly after 19z. Light westerly seabreeze this
afternoon with cigs returning after 06z.

SFO Bridge Approach...Approach clearing around 1930z then
remaining clear through evening rush.

Monterey Bay Terminals...Low clouds will slowly pull back by
20-21z for kmry then return around 02z this evening, staying in
place at least through 18z Tuesday.

&& of 8:00 AM PDT Monday...Light northwest winds are
forecast to prevail over the waters through the day with locally
breezy conditions along the Big Sur coast this afternoon and
evening. Generally light wind and seas will continue through
midweek. Northwest wind and seas will increase by Thursday or
Friday as a front approaches the far northern waters.


     .Tngt...SCA...Pt Pinos to Pt Piedras Blancas 0-10 nm until 9 PM




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NWS MTR Office Area Forecast Discussion