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

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FXUS66 KMTR 100503

Area Forecast Discussion
National Weather Service San Francisco CA
903 PM PST Sat Dec 9 2023


Issued at 1223 AM PST Sat Dec 9 2023

High pressure will bring quiet weather over the next several days.
Cold overnights and interior frost/freezing conditions are
expected this weekend before a gradual warming trend occurs early
next week.


Issued at 805 PM PST Sat Dec 9 2023

It`s another cool evening turning into a cold night. The Frost
Advisory goes in effect int the late night and will last through
Sunday morning. Temperatures will be slightly warmer than this
morning, but can still be hazardous. No major changes to the
forecast are expected.


(This evening through Sunday)
Issued at 110 PM PST Sat Dec 9 2023

All in all, pretty nice day across the Golden State with ample
sunshine most areas with a few clouds near the OR border.
Under ample sunshine max temps today will top out mainly in the
60s, which is slight above normal for this time of year. For what
it`s worth, latest 24 hour trends also show many spots running a
few degrees warmer than Friday.

The upper level ridge that began to move over the region
yesterday will continue through tonight. The ridge aloft will set
the stage for another night with radiational cooling. However, the
ridge of high pressure will also bring in a slightly warmer
airmass. Therefore, overnight lows for Saturday night will be a
tad warmer than last night. That being said, interior locations
will still reach the mid to lower 30s. Last nights Freeze Warning
has been replaced by a Frost Advisory for tonight.

Sunday will be relatively quiet - chilly start, but sunny skies
in the afternoon. Temperatures will warm a few more degrees with
max temps reaching the 60s to low 70s.


(Sunday night through next Friday)
Issued at 150 PM PST Sat Dec 9 2023

Heading into next week the upper level ridge flattens as a
shortwave trough moves through far NorCal Sunday night and Monday.
Mild and dry for Monday. As a second shortwave will push through
the PacNW and ultimately cut off from the main flow at 500 mb in
the form of an upper low by Tuesday. This upper feature will bring
in subtle cooling to the Bay Area as the upper low moves toward
the Desert SW mid-week.

The hype train has left the station for the extended. Lots of talk
regarding a notable jet panning the Pacific Basin the middle of
the month. At this point, CPC gives most of CA a slight risk for
heavy precipitation. Current forecast does bring rain back to the
region Friday night into the N Bay and the rest of the Bay Area
next Saturday. Lots to fine tune between now and then...


(06Z TAFS)
Issued at 902 PM PST Sat Dec 9 2023

Generally VFR through the TAF period, with the exception of low to
moderate confidence fog and low stratus Sunday morning in the North
Bay valleys and the far interior East Bay. Light offshore flow
overnight before onshore flow returns Sunday afternoon. Model output
shows low confidence for coastal stratus to redevelop on Sunday
evening, especially near the Petaluma Gap and Point Reyes, but not
enough confidence to include in the TAFs at this time.

Vicinity of SFO... VFR through the TAF period, with light offshore
flow overnight. Northwest flow returns Sunday afternoon.

SFO Bridge Approach... Similar to SFO.

Monterey Bay Terminals... VFR through the TAF period. Light drainage
flow overnight before north to northwest flow returns Sunday
afternoon with some breezy conditions at SNS.


(Tonight through next Thursday)
Issued at 902 PM PST Sat Dec 9 2023

High pressure bringing quiet and dry conditions to the region.
Light to moderate northerly breezes continue through the weekend
with seas of up to 6 to 8 feet. Fresh to strong breezes return to
the offshore waters by early to mid next week.


CA...Frost Advisory until 10 AM PST Sunday for CAZ506-516-518.




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