Weather Service Report


560 
FXUS66 KMTR 241802
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco Bay Area
1102 AM PDT WED AUG 24 2016

.SYNOPSIS...High pressure over the Eastern Pacific will keep
similar temperatures across the district today and Thursday.
Modest cooling is then expected late in the week and into the
upcoming weekend as a weak upper level trough develops over
California. A persistent marine layer will maintain night and
morning low clouds at and near the coast.

&&

.DISCUSSION...As of 8:20 AM PDT Wednesday... Visible imagery
shows summer stratus banked throughout the entire California
coastline and pushing into inland low lying valleys from Sonoma to
Monterey county. Temperatures are running a few degrees cooler
than yesterday morning beneath the stratus deck and temps are
expected to end the day with similar readings to yesterday. For
today and tomorrow, a vast majority of locations will be a few to
several degrees below normal, with only the most extreme inland
locations such as Pinnacles National Park expected to be somewhat
warmer than normal. Winds above the Soberanes fire will generally
be out of the northwest, which will push the vast majority of
lofted smoke towards the south-southeast and way from more
populated areas.

Meanwhile, a 594DM high pressure ridge remains amplified along the
Pacific coastline with the ridge axis lingering around 135W today.
This feature will remain quasistationary into tomorrow leading to
a continuation of the fair onshore weather already in place. 

The weather pattern shifts, but in no spectacular fashion, into
Friday as the aforementioned ridge begins to retrograde upstream
as a weak cutoff low undercuts it from the windward direction.
Then, weak mean troughing will develop over the PACNW and to a
lesser extent Northern and Central California later in the weekend
and into much of next week, with medium to long term models
indicating the potential for one of the more organized upper lows
we have seen for a while push into the region a few days into
September.

.PREVIOUS DISCUSSION...As of 2:50 AM PDT Wednesday...The marine
layer remains around 1500 feet deep, per the latest output from
the Fort Ord profiler. Satellite imagery shows low clouds have
spread into most inland valleys. Currently, area airports are not
indicating much fog - so far only Salinas airport is the only one,
with 9 miles visibility being reported.

A high pressure ridge will persist over the Eastern Pacific, just
off the West Coast. This will maintain seasonably warm
temperatures across the district: highs ranging from the 60s to
lower 70s at the coast, to the 80s and 90s well inland. By the end
of the week, an upper level trough is progged to dig westward into
Northern California from the northern Rockies. The result for our
area will be slightly cooler temperatures and a deepening marine
layer. By early next week, high pressure is forecast to rebuild
into Southern and Central California from the Desert Southwest.
This will edge max temperatures up a bit, although night and
morning low clouds and fog are expected to continue along the
coast.

&&

.AVIATION...As of 10:44 AM PDT Wednesday...For 18Z TAFs. Cloud
burn off has been lagging a bit this morning but visible
satellite now showing quick eroding taking place. Marine layer
persistent at around 2000 feet. VFR conditions expected for most
terminals by 18Z. No real change for tonight. Low CIGs return this
evening.

Vicinity of KSFO...VFR CIGs will prevail after 18Z. Will have to
monitor KOAK for clearing. Currently have clearing by 20Z...but
may have to AMD earlier if trends continue. Gusty onshore flow
this afternoon. Hi-res models show MVFR/IFR CIGs returning by 04Z-
05Z. Low to moderate confidence.

SFO Bridge Approach...Similar to KSFO.

Monterey Bay Terminals...VFR through this afternoon. Another round
of moderate onshore winds expected. Low CIGs come back around
03Z.

&&

.MARINE...as of 10:40 AM PDT Wednesday...Generally light to
moderate northerly winds will persist over the region as high
pressure remains aloft. Locally stronger and gusty onshore winds
are forecast north of the bay bridge this afternoon and evening. A mixed
swell will continue as a long period southerly swell impacts the
coastal waters.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .Tday...SCA...SF Bay from 2 PM

&&

$$

PUBLIC FORECAST: DRP
AVIATION: BAM
MARINE: RGass


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