FXUS66 KMTR 091804
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
1004 AM PST Mon Feb 9 2026
...New AVIATION...
.KEY MESSAGES...
Updated at 109 AM PST Mon Feb 9 2026
- Patchy fog this morning.
- Wetting rains expected Tuesday morning through Wednesday and
again next weekend. &&
.SHORT TERM...
Issued at 109 AM PST Mon Feb 9 2026
(Today and tonight)
As a very weak front exits the area to the southeast, surface
observations are showing winds becoming more northwesterly (except
for a few localized terrain differences). With increased mid and
upper level moisture, mostly cloudy to overcast skies are expected
through daybreak. This cloud deck and light winds around 5 mph
should help suppress radiational fog development. However, patchy
fog is still possible through daybreak this morning in the more
traditional spots that are more sheltered from the wind. At the
time, no advisory is expected, but will be monitored through the
morning.
As zonal flow aloft sets up today, conditions should be fairly
quiet. Temperatures are once again expected to climb into the 60s
with coastal areas remaining in the low 60s (or even upper 50s).
With increasing moisture aloft ahead of the next system, cloud
cover will remain keeping low chances for any fog development
overnight into Tuesday morning. Temperatures will drop down to the
low 50s along the coast and mid 40s for inland areas (with a
chance of localized low 40s for far interior locations).
An upper level is expected to move from the north Central Pacific
toward southern California today, inducing surface cyclogenesis
out over the ocean this afternoon. Models are showing fairly good
agreement that that surface low is expected to move toward Point
Conception before taking a left turn tomorrow morning and head
toward the Bay Area. It is this low that is expected to bring the
widespread soaking rain to the area. While the rain shadow will be
in effect, models continue to trend wetter with this low allowing
most of the area to get something though there is still some
uncertainty on exact amounts as this system starts to come into
the range of high res guidance. But with decent forcing, a strong
low level jet in the afternoon and orographic lift, the coastal
areas will likely sees the highest rain totals. Rain rates could
be up to 0.25" per hour in many of the stronger cells, with
localized rates up to 0.50" per hour closer to the center of the
low. Lastly, while instability is not overly strong, isolated
thunder cannot be completely ruled out in the late afternoon and
into Tuesday evening.
&&
.LONG TERM...
Issued at 109 AM PST Mon Feb 9 2026
(Tuesday through Sunday)
There is still some disagreement in model guidance on the exact
trend for the low, but most guidance as the low stalling out over
the ocean just west of the Golden Gate and weakening Tuesday night
through Wednesday. Rain will be come more scattered at times
overnight into Wednesday with breaks developing. That being said,
it looks Wednesday could be another wet day. With models still
disagreeing with the track and trend for the low, there is lower
confidence in the exact end time and could vary north to south
across the forecast area, as well as coastal vs. inland. But there
is a non-zero chance that light rain lingers through Thursday
morning, but impacts should be minimal. Lastly, cooler air is
expected to advect in behind the low. Temperatures will finally
return back to seasonal normals with highs in the 50s (maybe touch
low 60s?) and lows in the 40s.
Weak ridging Thursday into Friday morning should offer a brief
respite from the rain. However, Models are still suggesting
another upper level trough will move over the Bay Area and the
Central Coast. This trough is a much larger wave from a spatial
extent, which opens the door for smaller embedded waves to move
over the area setting up a pattern that trends towards rain being
a common theme for the extended forecast. At this distance, it is
hard to have confidence on the timing of not just the rain, but
any breaks in the rain, but it looks wet from Saturday onward.
Additionally, this system moving in overnight Friday into Saturday
is projected to have a colder airmass associated with it.
Freezing levels will lower opening the door for some snow
potentially at higher elevations. But even sheltered valley
locations are expected to have morning low temperatures in the mid
to upper 30s by early next week.
&&
.AVIATION...
(18Z TAFS)
Issued at 944 AM PST Mon Feb 9 2026
We'll have plenty of mid/upper clouds streaming overhead this
period, which means minimal concerns about fog for tonight into
Tuesday morning. Right now, there is a surface low located at
about 33N, 135W out in the Pacific that will push NE toward the
central CA coast Tuesday evening. As this low approaches the CA
coast, a band of rain will move onshore. However, based on the 12z
HREF, this rain looks to hold off in central CA until after 18z
Tuesday, so it's only SFO and OAK that have a rain mention with
this TAF set, with all other terminals getting in on the -RA
action with the 00z TAF set.
Vicinity of SFO...-RA will be pushing in Tuesday afternoon.
20z-23z currently looks like the window for -RA onset. With the
rain will also come the potential MVFR cigs, though RAP forecast
soundings don't really show MVFR cigs moving in until just after
Wednesday 00z, so kept cigs VFR for now, though did drop the vis
to MVFR with the precip. Another issue for SFO will be wind
directions. With the surface low approaching from the southwest,
we'll have a pressure gradient that will support southeast winds
that will have the potential to put the field into a southeast
configuration Tuesday afternoon and evening. Besides MVFR cigs,
just lurking beyond the end of this period will be the threat for
some TS Tuesday evening as well.
SFO Bridge Approach...No issues expected with visual approaches
until rain begins moving into the Bay area Tuesday afternoon.
Monterey Bay Terminals...As the low approaches from the southwest
and southerly 925mb winds begin to approach the CA coast, RAP
soundings do hint at the potential for some stratus coming in off
the Pacific between roughly 12z and 16z. For now, added that SCT
cloud group at 12z to cover this threat at MRY. It doesn't not
look to be an issue for SNS.
&&
.MARINE...
(Today through Saturday)
Issued at 241 AM PST Mon Feb 9 2026
Fresh to strong northwest breezes prevail across the coastal
waters today. A low pressure system will then approach from the
west bringing rain to the coastal waters and bays Tuesday through
Wednesday. Gale force gusts are possible on Tuesday in the waters
south of the Golden Gate depending on the strength and track of
the low. Rain chances return next weekend.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory from 9 AM Tuesday to 3 AM PST Wednesday for
Mry Bay-Pigeon Pt to Pt Pinos 0-10 nm.
Small Craft Advisory until 9 PM PST this evening for Pt Pinos to
Pt Piedras Blancas 0-10 nm.
Gale Watch from Tuesday morning through Wednesday morning for Pt
Pinos to Pt Piedras Blancas 0-10 nm.
Small Craft Advisory until 3 AM PST Tuesday for Pt Arena to Pt
Reyes 10-60 NM.
Small Craft Advisory from 9 PM Tuesday to 9 AM PST Wednesday for
Pt Arena to Pt Reyes 10-60 NM.
Small Craft Advisory until 3 PM PST this afternoon for Pigeon Pt
to Pt Pinos 10-60 NM.
Small Craft Advisory from 3 PM Tuesday to 9 AM PST Wednesday for
Pigeon Pt to Pt Pinos 10-60 NM.
&&
$$
SHORT TERM...KR
LONG TERM....KR
AVIATION...BFG
MARINE...DialH
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Prepared by Boulder-Creek.com Weather at: Mon Feb 9 10:30:03 PST 2026
From the National Weather Service
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