Area Forecast Discussion
Issued by NWS San Francisco Bay Area, CA
FXUS66 KMTR 261801
Area Forecast Discussion
National Weather Service San Francisco Bay Area
1101 AM PDT FRI AUG 26 2016
.SYNOPSIS...Very little change is expected to occur through the
weekend and through the middle of next week. Temperatures will be
near or slightly below normal through the period. Areas of night
and morning low clouds will give way to sunny skies by midday for
inland areas. Most coastal areas will continue to see widespread
low cloud cover persist through the daytime hours.
.DISCUSSION...As of 9:00 AM PDT Friday...Widespread clouds this
morning due to a deep marine layer (around 2,800 feet) plus an
onshore flow at the surface. Humidity readings also saw a large
increase for areas in the 2000 to 3000 foot level which should
help with fire fighting efforts. Due to the clouds and deeper
layer, highs will be cooler than normal -- 60s at the coast with
70s and 80s inland.
No major updates planned.
.PREVIOUS DISCUSSION...The marine layer has deepened, and is now
up to around 2200 feet per the Fort Ord profiler. Satellite fog
product imagery shows more low clouds over inland areas than seen
yesterday at this time, but that would make sense given the deeper
marine layer. Temperatures are warmer than 24 hours ago with most
readings in the upper 50s to lower 60s. Highs today are expected
to be cooler than yesterday in most areas with 60s at the coast,
and 70s and 80s inland.
Today is expected to be the coolest day...with slight warming
expected during the weekend as the upper trough over California
is replaced by a weak shortwave ridge. However, weekend
temperatures will remain cooler than average and widespread night
and morning low clouds with little, if any, coastal clearing
during the afternoon hours.
Medium range models bring a longwave trough along the West Coast
next week, deepening it during the week. This will maintain cool
temperatures through the period, but also may deepen enough to mix
out the coastal marine layer resulting in a little warmer weather
along the coast, a preview for fall.
.AVIATION...as of 10:48 AM PDT Friday...Low clouds quickly
dissipating over inland areas around the San Francisco Bay with
generally weak southerly winds. Cloud cover slower to burn-off
over the North Bay however. Meanwhile, low clouds persist over
much of the Monterey Bay Region as the marine layer remains around
2800 feet in depth. Thus, this area may remain under low clouds
through much of the day, potentially breaking out for a few hours
this afternoon. Onshore flow will increase slightly though
the afternoon and early evening with low clouds likely to spread
back inland late this evening and persist into Saturday morning.
Vicinity of KSFO...Low ceilings have scattered out over the
region this morning with variable to light southerly winds. Wind
speeds will then increase this afternoon out of the west/southwest
with the onset of the sea breeze. Low clouds likely to return
around 04Z this evening and will persist into Saturday morning.
SFO Bridge Approach...Similar to KSFO.
Monterey Bay Terminals...MVFR ceilings persist over the region
this morning and will likely remain in place through much of the
day. However, inland areas such as KSNS may scatter out briefly
this afternoon before low clouds spread back inland this evening.
Onshore winds will increase slightly through the afternoon as the
sea breeze develops.
.MARINE...as of 10:48 AM PDT Friday...A weak surface pressure
gradient across the coastal waters will maintain generally light
winds and seas through the weekend. Locally stronger and gusty
winds anticipated north of the Bay Bridge in the afternoon hours.
A mixed short period northwest swell and a long period southerly
swell will continue to impact the coastal waters.
.Tday...SCA...SF Bay from 1 PM
PUBLIC FORECAST: Bell/Sims
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