FXUS66 KMTR 040123
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
523 PM PST Wed Dec 3 2025
...New AVIATION, MARINE...
.KEY MESSAGES...
Updated at 1213 PM PST Wed Dec 3 2025
- Offshore winds relaxing through the day across the higher
elevations
- Benign conditions and no precipitation expected through the
next seven days
- Slight warming trend begins Friday through the weekend
&&
.SHORT TERM...
Issued at 1213 PM PST Wed Dec 3 2025
(This evening through Thursday)
Satellite imagery shows extensive high clouds across the Central
Coast, medium-level clouds across the Bay Area south of the Golden
Gate, and a thinner layer of high clouds across the North Bay.
Across the higher elevations, strong northeasterly winds continue to
gust up to 45 to 50 mph across favored locations, more generally
around 25 to 35 mph. These are being driven by the interaction
between a positively tilted trough extending from the Upper Midwest
into the Desert Southwest and an upper level ridge off the coast of
the Pacific Northwest and British Columbia. The combination results
in northerly flow over the region and a offshore pressure gradient,
although with the trough starting to move eastwards, the gradient is
gradually relaxing. The SFO-WMC gradient, which peaked at -8.9 mb as
of 7 AM this morning, has slackened to -6.3 as of Noon. Model
guidance shows the gradient continuing to gradually relax over the
next 24 hours. Another push of offshore flow is expected tonight,
but the gusts will not be as strong and the winds should return to a
more northwesterly onshore flow tomorrow.
High temperatures today and tomorrow will hover in the upper 50s to
the middle 60s for the lower elevations, down to the lower to middle
50s in the higher elevations. Lows will reach the upper 30s to the
lower 40s in the inland valleys, and into the middle to upper 40s
along the coast. Chilly lows in the lower to middle 30s are expected
in the southern reaches of Monterey County, but the coverage is not
widespread enough, especially across the southern Salinas Valley, to
issue a Cold Weather Advisory.
&&
.LONG TERM...
Issued at 1213 PM PST Wed Dec 3 2025
(Thursday night through next Tuesday)
The forecast conditions remain remarkably stable with the conditions
remaining generally dry and benign through the 7 day outlook.
Although a couple of storm systems will impact the West Coast, the
upper level flow will divert them to the north. As a result, while
the Pacific Northwest and the North Coast see a couple shots of
rain, the current forecast depicts the rain chances for our part of
the state remaining offshore, sometimes tantalizing close to the
shoreline. The eastern Pacific ridge will build into the
southwestern US during this time, allowing a gradual warming trend
to begin on Friday and last through the weekend. By the early part
of next week, temperatures in the inland valleys could rise into the
upper 60s to lower 70s, with the coast remaining in the lower to
middle 60s.
The next chance for substantial rainfall across the region lie
closer to the middle of the month, and at this point in the
forecast, the uncertainty can be best described as "Here be
dragons". Considering that the moisture to power such a system
currently lies in the western Pacific and the parent low pressure
system has yet to form over Asia, this is not surprising.
&&
.AVIATION...
(00Z TAFS)
Issued at 523 PM PST Wed Dec 3 2025
Light, generally light offshore winds and VFR conditions continue
through the TAF period. Sites are running anywhere between 15% to
50% drier today than they were at this time yesterday. This influx
of dry air should keep both marine stratus and foggy conditions away
from our area tonight. The one concern would be if any Tule Fog is
able to redevelop and move into the delta/towards APC. Not currently
expecting this to occur but it is a possibility if fog is able to
redevelop in the Central Valley. A weak sea breeze is possible
tomorrow afternoon and evening again.
Vicinity of SFO...VFR through the TAF period. A weak sea breeze is
expected to develop this afternoon/evening and again tomorrow
afternoon/evening. Otherwise, winds largely remain light and
offshore through the TAF period. Not expecting any low clouds or fog
either at SFO or along the Bridge Approach.
SFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...VFR. Winds remain lightly onshore through
the rest of the evening before becoming offshore again overnight.
Winds transition to lightly onshore/more northerly by late tomorrow
morning/early tomorrow afternoon.
&&
.MARINE...
(Tonight through next Tuesday)
Issued at 523 PM PST Wed Dec 3 2025
Moderate NW winds will persist through the afternoon and decrease
to a gentle breeze by Thursday. Rough seas in the outer waters
will gradually diminish overnight as the winds ease and westerly
swell abates. After a brief favorable weather window on Thursday,
northerly winds will increase to a fresh to strong breeze on
Friday, rebuilding moderate seas up to 8 feet.
&&
.BEACHES...
Issued at 425 AM PST Wed Dec 3 2025
A Beach Hazards Statement remains in effect for the coastline
from Sonoma County to Monterey County through 10 PM PST Wednesday
evening. Breaking waves 10 to 14 feet, with long lulls of 10 to 20
minutes or more between largest sets can be expected. Some of the
favored break points may exceed 20 feet at times. Forerunners
will be 18+ seconds with heights of 2-5 feet into tonight
resulting in the greatest risk for sneaker waves. This combined
with high astronomical tides in the morning hours will increase
the aforementioned risk. 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.
RGass
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement until 10 PM PST this evening for CAZ006-
505-509-529-530.
Coastal Flood Advisory until 3 PM PST Sunday for CAZ006-506-508-
529-530.
PZ...Small Craft Advisory from 9 PM Thursday to 3 PM PST Friday for
Pt Arena to Pt Reyes 10-60 NM.
&&
$$
SHORT TERM...DialH
LONG TERM....DialH
AVIATION...Kennedy
MARINE...Flynn
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Prepared by Boulder-Creek.com Weather at: Wed Dec 3 18:30:01 PST 2025
From the National Weather Service
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