FXUS66 KMTR 220514
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
914 PM PST Fri Nov 21 2025
...New AVIATION...
.KEY MESSAGES...
Updated at 1220 PM PST Fri Nov 21 2025
- Very quiet with fair weather through this weekend.
- Marine stratus returning Saturday night, but clear during the
days through early next week.
- Details very unclear, but high likelihood of a western US
pattern change after Thanksgiving.
&&
.UPDATE...
Issued at 902 PM PST Fri Nov 21 2025
Clear skies are observed this evening courtesy GOES-18 satellite
imagery. Temperatures have gradually been falling with valley and
coastal areas in the mid 40s to low 50s, while areas of higher
terrain have dipped into the upper 30s to upper 40s. Overnight
lows will feel a bit cool or crisp as valley and coastal areas
primarily fall into the 40s, and areas of higher terrain fall
into the mid 30s to mid 40s.
&&
.SHORT TERM...
Issued at 1220 PM PST Fri Nov 21 2025
(This evening through Saturday)
There almost isn't a cloud in the sky across our entire 11 county
warning area this afternoon. Light offshore flow and large scale
subsidence are paving the way for fair weather through at least
the next 24 hours. Saturday looks like it'll be a copy/paste from
today with the only exception being marine stratus filling in
along the coastline Saturday evening.
&&
.LONG TERM...
Issued at 1220 PM PST Fri Nov 21 2025
(Saturday night through next Thursday)
Not much change in the long term today. Continued cool temps
within a degree or two of normal through the rest of the weekend
and early part of next week. High confidence in a broad ridge over
the western US into Thanksgiving, which would allow fair weather
to persist and result in a very gradual warming trend by a few
degrees into late week. Probably not even noticeable by most.
Looking at the end of the period is where we find our next
interesting weather feature. Long term ensemble guidance continues
to advertise a very deep, closed upper low digging into the SW US
from Canada. At this point, the spread of model solutions
diverges so much that it's not worth trying to pin down anything
specific at this point. Possibilities range from a very prolific
rain maker to a nothing burger with light offshore winds again.
What's the take-away here? Confidence is high that there will be
a strong storm system digging its way into the Western US sometime
around next weekend. Confidence is very low regarding where it'll
set up and how much it'll dig to the SW. One other feature that
has been persistent in model solutions is a very high amplitude
ridge over the eastern Pacific up into AK and northwest Canada.
This reinforces the signal that there will be a deep upper low
downstream over the western US. Be sure to stay tuned to the
forecast over the next few days as details on this system become
more clear.
&&
.AVIATION...
(06Z TAFS)
Issued at 914 PM PST Fri Nov 21 2025
Dry weather supports ongoing high confidence VFR forecast for the
evening. For tonight and Saturday morning VFR continues at most
terminals, however longer night-time radiative cooling hours and
residual boundary layer humidity may combine to produce fog
patches, possibly including dense fog /VLIFR-IFR/. The WMC-SFO
pressure gradient and nocturnal cool/cold air drainage winds
support east to southeast winds which may also transport dense
tule fog from the Central Valley to portions of the East Bay late
tonight and Saturday morning. Patchy morning fog Saturday,
otherwise VFR.
Vicinity of SFO...VFR. Mainly light and variable wind tonight and
Saturday morning, becoming west 5 to 10 knots Saturday afternoon
and evening.
SFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...VFR. Winds becoming light southeast
tonight and Saturday morning then west near 10 knots Saturday
afternoon and early evening.
&&
.MARINE...
(Tonight through next Thursday)
Issued at 902 PM PST Fri Nov 21 2025
A high pressure system will build in from the northwest through
early next week. While winds diminish, hazardous marine conditions
will continue into the weekend as seas will remain moderate.
Elevated seas will be prolonged by the arrival of long period
northwesterly swell.
&&
.BEACHES...
Issued at 919 AM PST Fri Nov 21 2025
A Beach Hazards Statement is in effect through Monday evening. A
long period northwesterly swell will result in an increased risk
for sneaker waves and rip currents. Breaking waves of 13 to 18
feet are expected. Sneaker waves can unexpectedly run
significantly farther up the beach than normal, including over
rocks and jetties. Rip currents are typically more frequent and
stronger in the vicinity of jetties, inlets, and piers.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement through Monday evening for CAZ006-505-
509-529-530.
PZ...Small Craft Advisory until 3 AM PST Sunday for Pigeon Pt to Pt
Pinos 10-60 NM-Pt Arena to Pt Reyes 0-10 nm-Pt Arena to Pt
Reyes 10-60 NM.
&&
$$
SHORT TERM...Behringer
LONG TERM....Behringer
AVIATION...Canepa
MARINE...Canepa
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Prepared by Boulder-Creek.com Weather at: Fri Nov 21 22:30:03 PST 2025
From the National Weather Service
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