FXUS66 KMTR 032014
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
1214 PM PST Wed Dec 3 2025
...New SHORT TERM, LONG TERM...
.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...
(18Z TAFS)
Issued at 923 AM PST Wed Dec 3 2025
Another nice day to fly. High confidence in VFR conditions
through the TAF period. Offshore winds will continue for most
terminals, with a weak sea breeze likely to develop in the
afternoon. Easterly winds could be gusty overnight, but the
sustained winds should be gentle all day. High clouds will persist
through the TAF period for all terminals, but low clouds are very
unlikely with the dry, offshore flow.
Vicinity of SFO...VFR conditions through the TAF period. A gentle
SE wind may shift to NE at times through the late morning. By 00Z,
there is a good chance for a sea breeze to flip the wind direction
to westerly, but that's not a guarantee. The 16Z GFSLAMP guidance
does not have any onshore wind component throughout the forecast.
The TAF however nods to what happened yesterday under a similar
mesoscale set-up and eventually brings a sea breeze this evening.
SFO Bridge Approach...Persistent high clouds should remain well
above the approach.
Monterey Bay Terminals...VFR conditions through the TAF period.
Offshore winds should flip to northerly by early afternoon before
sliding back to easterly overnight.
&&
.MARINE...
(Today through Monday)
Issued at 923 AM PST Wed Dec 3 2025
Moderate NW winds will persist through the day 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 until 3 PM PST this afternoon for Pt Arena
to Pt Reyes 10-60 NM.
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...Flynn
MARINE...Flynn
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Prepared by Boulder-Creek.com Weather at: Wed Dec 3 14:30:02 PST 2025
From the National Weather Service
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