Millbrae, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

251
FXUS66 KMTR 251344
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
544 AM PST Thu Dec 25 2025

...New UPDATE...

.KEY MESSAGES...
Updated at 1052 PM PST Wed Dec 24 2025

 - Strong and damaging winds continue overnight through Thursday
   evening.

 - A flood watch remains in effect through Friday evening across
   the region. The main threat is flash flooding and landslides
   from high rain rates.

 - Slight chances for severe thunderstorms begin this evening and
   continue through Thursday evening. Severe threats include
   damaging wind gusts and possible tornadoes.

 - Dangerous beach and marine conditions continue through Friday
   across the Pacific coast and adjacent beaches.

 - Cold temperatures settle in this weekend after the storms break

&&

.UPDATE...
Issued at 532 AM PST Thu Dec 25 2025

The main rain band has passed to the east of us. Severe
Thunderstorm Warnings and Flash Flood Warnings were issued
overnight across the Bay Area as the damaging winds and intense
rain came through the region. Wind gusts remain elevated across
the region, and the immense rainfall is still making its way
across the urban landscape of the Bay Area. We are continuing to
receive reports of roadway flooding across the Bay Area. If you
come across a flooded roadway, turn around, don`t drown! Even if
you don`t, take care if you do have to travel across the region
today, as the intense winds brought down trees, branches, and
power lines across the roadways.

Scattered showers continue through the morning with the latest
high resolution guidance showing a signal for some organized
thunderstorms to return late this afternoon and this evening as a
shortwave approaches the state.

Highest wind reports overnight are 92 mph at the North Peak
Access Road PG&E station in northwestern San Mateo County, 91 mph
at the O`Neill Sea Odyssey station near Santa Cruz harbor, and 90
mph at the Mount Umunhum PG&E station and the Gunsight Fire Road
PG&E station in the Marin County highlands. Downtown San Francisco
reported 0.74 inches of rain from 5 PM yesterday to 5 AM this
morning.

DialH

&&

.SHORT TERM...
Issued at 1052 PM PST Wed Dec 24 2025
(Tonight through Friday)

Don`t let your guard down, the line of showers and thunderstorms
with strong winds that swept through our area earlier this
(Wednesday) evening was only a precursor to what is expected to
be the most impactful line of storms yet, that is currently about
to enter our outer marine zones about 100mi offshore. Impacts for
the next line are expected to be felt by Midnight PST, with
another round of strong wind, periods of heavy rain with the
potential of low top supercells producing waterspouts that could
move onshore as short-lived tornadoes or straight line winds up
to 80 MPH or higher. The High Wind Warning remains in place until
10 AM PST Thursday (Christmas) morning and may be extended. Our
Flood Watch remains in place until Friday night at 10 PM PST. The
SPC continues to have our entire Pacific Coast line in a Marginal
Risk for Severe Thunderstorms through early Friday morning at 4
AM. That means, the line off showers and thunderstorms progged to
move onshore as early as late afternoon Thursday into the evening
hours may be just as impactful as the one currently on our door
step. That means all hazards mentioned above are in play through
at least tomorrow night, along with the dangerous beach hazards
and gale to near storm force winds over both our coastal and outer
waters. If traveling Christmas day or night, expect extensive
travel delays, along with power outages and urban/nuisance
flooding.

&&

.LONG TERM...
Issued at 1052 PM PST Wed Dec 24 2025
(Friday night through next Wednesday)

*Long term discussion remains unchanged from Wednesday afternoon
 update*

Starting in the early morning Friday, winds and shower activity
will gradually decrease as the low pressure system offshore opens
up into a trough and moves into northern Oregon. The associated
surface trough axis will move across the Bay Area Friday evening.
This will finally flip the winds back to northerly, bringing
drier, cooler weather for the weekend. The 1000-500 mb thickness
actually increases this weekend, with the cooling coming mainly from
enhanced radiation during in the cloudless nights. Sunday through
Tuesday look particularly calm, clear and cool as a 500 mb ridge
sets in. The next troughing pattern looks probable on the 1st or
2nd, just in time for King Tides. There`s no strong signal for
major impacts yet, but the CW3E ECCC AR Activity tool shows higher
than normal chances for atmospheric rivers through the first half
of January.

&&

.AVIATION...
(12Z TAFS)
Issued at 347 AM PST Thu Dec 25 2025

The main band of intense rain and wind is making its way through the
East Bay, South Bay, and the northern Monterey Bay region. It is
expected to cointinue pushing eastwards through the next couple of
hours. Behind the band, lighter rain prevails with winds remaining
rather breezy, with a chance for showers continuing through the day.
Mix of MVFR and VFR with mid-level clouds should prevail outside the
convective activity, and the winds should continue to diminish
through the TAF period.

Vicinity of SFO... Winds should continue to be rather gusty from a
generally south to southeast direction through the TAF period, with
MVFR to VFR with mid-level clouds prevailing. Gusts will top out
around 35 kt through the morning, diminishing to 20 kt in the
afternoon and evening hours. Chances for post-frontal convective
showers continue through the TAF period.

SFO Bridge Approach... Similar to SFO.

Monterey Bay Terminals... Latest high resolution model output shows
that the frontal line might not be as impactful in the Monterey Bay
region compared towards the north. If it does hold through, the
timeframe for impacts will be 13-15Z. Otherwise, generally southeast
winds will continue through the rest of the TAF period with gusts up
to 25 kt, scattered showers and generally MVFR to VFR with mid-level
ceilings.

&&

.MARINE...
(Today through Tuesday)
Issued at 347 AM PST Thu Dec 25 2025

...HAZARDOUS MARINE CONDITIONS CONTINUE INTO EARLY FRIDAY...
Southeast gales across the coastal waters continue through the
pre-dawn hours of Friday morning. These dangerous winds are
accompanied by a chance for thunderstorms and possible waterspouts
through the early morning hours. Seas will rebuild to very rough
from the choppy wind waves. These hazardous seas will linger
through Friday, reinforced by a moderate westerly swell. If your
vessel is not able to handle these conditions return to port or
seek protected waters as soon as possible.

&&

.BEACHES...
Issued at 325 PM PST Wed Dec 24 2025

A Beach Hazards Statement has been issued for the coast through
4AM Friday. The main concerns include:blowing and drifting sand
and wind waves up to 20 ft. The drifting sand and increased sea
spray will also result in poor visibilities, affecting water
rescues. Increased coastal erosion will be possible as well.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement through late tonight for CAZ006-505-509-
     529-530.

     Flood Watch through Friday evening for CAZ006-502>506-508>510-
     512>518-528>530.

     High Wind Warning until 10 AM PST this morning for CAZ006-503-
     505-509-517-528>530.

     Wind Advisory until 10 AM PST this morning for CAZ502-504-506-
     508-510-512>516-518.

PZ...Gale Warning until 3 AM PST Friday for Mry Bay-Pigeon Pt to Pt
     Pinos 10-60 NM-SF Bay N of Bay Bridge.

     Storm Warning until 3 AM PST Friday for Pigeon Pt to Pt Pinos 0-
     10 nm-Pt Arena to Pt Reyes 0-10 nm-Pt Arena to Pt Reyes 10-
     60 NM-Pt Pinos to Pt Piedras Blancas 0-10 nm-Pt Reyes to
     Pigeon Pt 0-10 nm.

&&

$$

SHORT TERM...JM
LONG TERM....JM
AVIATION...DialH
MARINE...DialH

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