FXUS66 KMTR 111744
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
944 AM PST Thu Dec 11 2025
...New AVIATION...
.KEY MESSAGES...
Updated at 1110 PM PST Wed Dec 10 2025
- Hazardous beach conditions through Friday
- Tule fog and stratus continue for the North and East Bay
- Wetter pattern expected to begin next week
&&
.UPDATE...
Issued at 833 AM PST Thu Dec 11 2025
Very similar set up to this time yesterday as low clouds and/or fog
persist over much the valley locations in the North Bay, East Bay,
and South Bay. Seeing a bit more coverage across San Francisco and
around the west side of the Bay Shoreline, however these conditions
are expected to improve within the next few hours. Late afternoon
clearing is also expected across much of the region, except across
the far interior East Bay, southern portions of Napa and Sonoma
County, and bay side areas of Marin County. Otherwise, the ongoing
forecast remains on track at this time with no updates anticipated.
RGass
&&
.SHORT TERM...
Issued at 1110 PM PST Wed Dec 10 2025
(Tonight through Friday)
Different day, same weather. Tule fog continues to fill the Central
Valley with spill over through the Delta and across the Valleys in
the East Bay and North Bay. The visibility is already less than a
mile at Livermore and Santa Rosa airports with a good chance to
worsen through the night. As we've seen over the last several
days, the fog and clouds should erode for most in the afternoon,
but may linger along the Delta and San Pablo Bay regions. Anywhere
in the fog will continue to deal with cold temperatures while
those areas in full sunshine will quickly warm well above normal.
The 00Z sounding found a surface temperature of 56 degrees while
the temperature at 3,000 feet was 70 degrees. This strong
inversion continues to make the max temperature forecast
challenging with some areas up to 10 degrees cooler than normal
and others up to 10 degrees warmer. We continue to rely heavily on
the persistence forecast which has been performing better than
any model recently.
&&
.LONG TERM...
Issued at 1110 PM PST Wed Dec 10 2025
(Friday night through next Wednesday)
The forecast remains fairly consistent through Friday before the
ridge axis finally slides to our East. This won't have a drastic
effect immediately, but the temperatures should cool a couple
degrees through the weekend. By Sunday or Monday we should start
to see some high clouds, indicating that the ridge has flattened
and zonal flow has moved in. This new pattern should help scour
out the persistent fog. We also expect some light rain early next
week, particularly across the North Bay. The most interesting
development in the forecast is in the extended long range, where
there is a moderate chance for an atmospheric river late next
week. It's too early to talk about specific impacts or timing, but
the Climate Predication Center has placed the Bay Area in a
moderate risk for both heavy precipitation and strong winds from
12/18-12/21. The bullseye looks like far northern California, but
that has been trending south over the last few model updates.
&&
.AVIATION...
(18Z TAFS)
Issued at 937 AM PST Thu Dec 11 2025
Sounding like a broken record, but aviation impacts again this
morning for N, E, and S Bay Terminals due to IFR conditions
(cigs/fg). Similar to yesterday, patchy clouds were hit or miss
inside SF Bay and that is the case again this morning. N and E Bay
will be last to clear for KSTS,KAPC,KLVK. KSJC will be late
morning for clearing. Monterey Bay terminals remains VFR. For
tonight, will lean toward persistence, but as high pressure
continues to build overhead the cloud deck will become more
compressed leading to lower cigs and potential for more fog.
overall conf is moderate.
Vicinity of SFO...Feed south of the terminal drift north bringing
IFR condition. Thankfully they'll be temporary. VFR expected this
afternoon. No cigs in taf for tonight.
SFO Bridge Approach...Similar to SFO. Slantwise vis could be
reduced again this afternoon.
Monterey Bay Terminals...VFR
&&
.MARINE...
(Today through Tuesday)
Issued at 833 AM PST Thu Dec 11 2025
High pressure off of the coast will maintain northerly fresh
breezes across the outer coastal waters with light to gentle
breezes near shore. Light offshore winds will continue from the
Delta to the San Francisco Bay and through the Golden Gate. A new,
long period northwesterly swell will last into this weekend.
&&
.BEACHES...
Issued at 1110 PM PST Wed Dec 10 2025
Long period NW swell is causing hazardous beach conditions
through Friday. This energy brings strong rip currents, an
increased risk for sneaker waves, and large breaking waves. This
coincides with nice warm weather, which will likely lure more
people to the beach under a false sense of security. A Beach
Hazard Statement is in effect through Friday evening. Respect the
power of the ocean and never turn your back on it.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement through Friday evening for CAZ006-505-
509-529-530.
PZ...Small Craft Advisory until 3 PM PST this afternoon for Pigeon Pt
to Pt Pinos 10-60 NM-Pt Arena to Pt Reyes 10-60 NM.
&&
$$
SHORT TERM...Flynn
LONG TERM....Flynn
AVIATION...RGass
MARINE...RGass
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Prepared by Boulder-Creek.com Weather at: Thu Dec 11 12:30:03 PST 2025
From the National Weather Service
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