981
FXUS66 KMTR 071755
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
955 AM PST Sun Dec 7 2025

...New AVIATION...

.KEY MESSAGES...
Updated at 320 PM PST Sun Dec 7 2025

 - Benign conditions through the next seven days with a gradual
   warming trend

 - Impacts from Tule Fog continue in the North Bay and interior
   East Bay valleys, with potential for expansion across the rest
   of the Bay Area tonight

 - Next chance for rain towards the middle of the month

&&

.UPDATE...
Issued at 900 AM PST Sun Dec 7 2025

Satellite imagery shows the stratus continuing across the Bay Area
valleys with the Central Coast remaining mostly clear. The 24-hour
comparison shows a very similar pattern to the stratus coverage
for this time yesterday, with the differences mainly lying in the
immediate coastal regions and, to the north of our area of
responsibility, across the valleys of Mendocino and Lake counties.
Leaning towards a more similar forecast for the evolution of the
stratus today. Considered tamping down the high temperature
forecast in the North and East bay valleys even further, but opted
to wait until afternoon forecast update to see how the stratus
evolves. No changes to the forecast.

DialH

&&

.SHORT TERM...
Issued at 321 AM PST Sun Dec 7 2025
(Today and tonight)

Rinse and repeat kind of weather for the short term. Very similar
to what was observed 24 hours ago in the broader scheme of things.
Longwave pattern continues to show broad upper level ridging off
the CA coast nosing its way into CA. A few high clouds are riding
the northern periphery of the ridge. At the surface is where the
impactful weather continues with and stratus covering the North
Bay, East Bay, and portions of the Bay Area. Tule Fog is sneaking
in from the Central Valley into the West Delta, North and East
Bay. Patchy dense fog will be possible through mid morning with
vsby less than one mile at times. The Central Coast on the other
hand remains cloud free.

Stratus didn`t really clear yesterday over the North Bay so that
is the question for today? Will Santa Rosa see some sunshine?
Latest guidance says yes, but very late in the day. As such,
undershot max temps from the NBM for the North and East Bay with
highs struggling to reach 50 degrees. Other locations will see
more sunshine and warming temperatures into the mid 50s and 60s.

Expecting a similar pattern again tonight with some stratus and
intruding Tule Fog.

&&

.LONG TERM...
Issued at 321 AM PST Sun Dec 7 2025
(Monday through Saturday)

No major updates for the extended as we`re locked in with this
ridge of high pressure dominating the overall weather through at
least next Friday. That means, some night and morning clouds like
we`ve been having. Tule Fog will still advect into the Bay Area
from time to time. The ridge is expected to build with higher
heights. The stratus deck will compress with a gradual warming
trend over the region. Still looking at 70 plus degrees across the
Central Coast Tuesday through Friday. The amount of clouds cover
over the North and East Bay will likely impact max temps and
limit warming potential early in the week, but ease as the high
pressure builds.

Rain chances still exist for the middle of the month, but odds
are decreasing. Latest CPC has backed off with near normal or
below normal chances for precip through December 20.

&&

.AVIATION...
(18Z TAFS)
Issued at 955 AM PST Sun Dec 7 2025

Tough forecast given the Tule fog and associated stratus have not
been handled well by the models. In fact, most of them for today are
fairly optimistic, which seems unlikely for much of our service Bay
Area terminals. The marine layer looks to be 1000-1500ft, with the
Valley being socked in as of this discussion. Expect cloudy
conditions to prevail for most sites, with CIGS varying from LIFR to
IFR. The exception might be KOAK, KSFO, and KSJC where onshore flow
might be able to mix things out. Where skies are clear, KHAF,
elevations above 1500ft, and the majority of the Central Coast, VFR
conditions will prevail.


Vicinity of SFO...Low to medium confidence in the forecast here
as most models have indicated some clearing by now and what we
have seen so far is a slight lift in CIGs. Satellite imagery
shows some clearing over the San Francisco Bay, but outside of
that there doesn`t appear to be much movement. The most
pessimistic of forecasts looks to be the MOS guidance from the EC,
which has loosely been incorporated in the TAF for clearing
around 21Z. After that, opted to keep the previous forecaster`s
TAFs in shape if the onshore flow pans out. Should it not, and we
stay socked in. The question if that happens will be how long do
we stay with IFR cigs? Low to medium confidence on this forecast.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...Light and variable offshore winds become
onshore by this afternoon, before circling back to offshore or light
variable tonight. No VIS or CIG concerns, thus VFR prevail. &&

.MARINE...
(Today through Friday)
Issued at 900 AM PST Sun Dec 7 2025

Moderate to fresh north to northwest winds hold for much of the
waters today with strong gusts focused on the southern waters.
Moderate seas with wave heights 6 to 8 feet across the outer
waters today, subsiding to around 4 to 6 feet for Monday. Winds
increase on Tuesday, with strong to near gale force gusts possible
for much of the waters. A new, long period northwesterly swell is
anticipated by Wednesday of next week.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Coastal Flood Advisory until 3 PM PST this afternoon for CAZ006-
     506-508-529-530.

PZ...Small Craft Advisory from 3 PM Monday to 3 AM PST Tuesday for
     Pigeon Pt to Pt Pinos 0-10 nm-Pigeon Pt to Pt Pinos 10-60
     NM-Pt Arena to Pt Reyes 0-10 nm-Pt Arena to Pt Reyes 10-60
     NM.

     Small Craft Advisory from 3 PM this afternoon to 9 PM PST this
     evening for Pigeon Pt to Pt Pinos 0-10 nm.

     Small Craft Advisory until 3 AM PST Tuesday for Pt Pinos to Pt
     Piedras Blancas 0-10 nm.

     Small Craft Advisory until 9 PM PST this evening for Pigeon Pt
     to Pt Pinos 10-60 NM.

&&

$$

SHORT TERM...MM
LONG TERM....MM
AVIATION...KR
MARINE...KR

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