Area Forecast Discussion
Issued by NWS San Francisco Bay Area, CA

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FXUS66 KMTR 180954

Area Forecast Discussion
National Weather Service San Francisco Bay Area
254 AM PDT Fri Aug 18 2017

.SYNOPSIS...Look for one more day of minor warming today as a
ridge of high pressure continues to build into our region. Minor
cooling can be expected over the weekend into next week as an
upper level low and shortwave trough move into our region.
Overnight clouds can be expected especially along the coast.

&& of 3:00 AM PDT Friday...for the first time in
quite awhile, satellite shows that clouds are fairly limited
across our region with even Monterey Bay cloud-free at this hour.
Satellite does show clouds finally advancing toward the coast and
with a westerly gradient nearly 3 MB, we should see them at least
advance to the coast before sunrise. Synoptically a ridge of high
pressure will move across our region today which will lead to a
few degrees of warming. Temperatures will be in the 60s and 70s at
the coast with 80s and 90s inland.

The ridge will be replaced by an upper level low and a shortwave
trough that will dive down from the north. This will lead to
cooling over the weekend and next week with most spots dropping 5
to 10 degrees. Clouds will also be likely each night especially
near the coast. Big question will be how much the marine layer
will change with the low overhead. Could be a case of the marine
layer mixing out. Regardless, next week is shaping up to be very
quiet with temperatures near normal.


.AVIATION...As of 10:30 PM PDT Thursday...Onshore gradients have
become more east-west this evening and stratus is starting to
spread into the northern SFO Bay Area and the North Bay. Cigs are
expected into SFO OAK and STS tonight but a southeast wind should
keep it out of SJC. The marine layer is expected to compress
further overnight and will lead to earlier clearing on Friday.

Vicinity of KSFO...MVFR after 10Z.

SFO Bridge Approach...Similar to KSFO.

Monterey Bay Terminals...Stratus has remained well offshore
through the early evening hours. In the past this usually meant
the MRY Bay Area would remain clear all night. Cigs have been
removed from the latest tafs.

&& of 10:30 PM PDT Thursday...A 1027 mb high is
centered 750 miles west of Cape Mendocino. A ridge will build from
this high into the Pacific Northwest this weekend. This will
result in increasing northwest winds over the northern waters.






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