FXUS66 KMTR 091139
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
339 AM PST Mon Feb 9 2026
...New AVIATION, MARINE...
.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.
&&
.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...
(12Z TAFS)
Issued at 339 AM PST Mon Feb 9 2026
A few localized terminals still have clouds below 1000 feet
lingering this morning; however, there is low confidence in those
clouds lasting for very long past daybreak. VFR is expected
through the TAF window. Winds should mostly be at or below 10
knots and out of the north-northwest.
There is a rainy system approaching the airspace Tuesday morning.
The probability for rain at any terminal was below 30 percent
through 12Z and thus was kept out of the TAF for the time being.
Vicinity of SFO...Lingering FEW clouds below 1000 feet should
clear out after daybreak. VFR conditions through the TAF window,
though increasing clouds at or below 2000 feet is expected after
12Z tomorrow morning. Winds will be mainly out of the north-
northwest, though it is possible that they flip slightly east of
north for a window in the afternoon. There was consideration for
adding a PROB30 group for rain between 12-18Z, but confidence in
timing was low and the better chances for rain are after 18Z.
SFO Bridge Approach...Similar to SFO.
Vicinity of SJC and OAK...Lingering FEW clouds below 1000 feet
should clear out after daybreak. VFR conditions through the TAF
window. Winds will be out of the north-northwest and under 10
knots, becoming light overnight. Consideration was given to adding
a PROB30 group at KOAK for rain between 12-18Z, but confidence in
timing was low and the better chances for rain are after 18Z.
Monterey Bay Terminals...MVFR cigs have developed around KSNS,
but LIFR cigs are clinging to the peninsula and KMRY. There is
better confidence in clearing for KSNS later this afternoon.
Model guidance has cigs slowly improving at KMRY, but lower
confidence on the exact timing to VFR. Light north-northwest winds
are expected this afternoon before becoming southeast overnight.
&&
.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.
Small Craft Advisory from 9 AM Tuesday to 9 AM PST Wednesday 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...DK
LONG TERM....DK
AVIATION...DK
MARINE...DialH
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Prepared by Boulder-Creek.com Weather at: Mon Feb 9 04:30:03 PST 2026
From the National Weather Service
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