FXUS66 KMTR 090130
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
530 PM PST Sun Feb 8 2026
...New AVIATION, MARINE...
.KEY MESSAGES...
Updated at 234 PM PST Sun Feb 8 2026
- Rain chances (30-50%) through this evening mainly confined to
northern portions of Sonoma county.
- Wetting rains expected Tuesday into Wednesday and again next
weekend.
- Active weather pattern begins this weekend and continues
through next week.
&&
.SHORT TERM...
Issued at 234 PM PST Sun Feb 8 2026
(This evening through Monday)
The main cold front this afternoon is visible on satellite as a line
of cumulus that extends from Mendocino county southwest out into the
Pac Ocean. The interesting feature though is the atmospheric bore
that has ripping out ahead of the cold front, running out on top of
the marine layer. As it moved across Point Reyes tower camera, the
stratus came through with a bit of drizzle as well. RAP Bufkit
soundings in the Bay area look to have picked up on this bit of
moisture, with SFO/OAK/SJC all showing a brief uptick in saturation
in the low level saturation, so you can't rule out a brief hit of
stratus/drizzle in the Bay area as this bore moves in, though likely
fizzles out as it begins to interact with the land.
As for the main precipitation shield with this front, water vapor
imagery shows a deep plume of moisture moving into Oregon and
Washington, with models continuing to keep the main synoptically
forced rain region remaining farther norther. In addition, low and
mid-level simulated WV imagery from special WOFs runs shows a wedge
of dry air moving in across central California to the south of the
main moisture plume up in Ore/Wash. This dry air shows up in
forecast soundings as a wedge of very dry air from h85 to h7 that
will keep it dry through this area. Also drying out on forecast
soundings are the low levels, with fog looking much less certain
tonight than what we had this morning. Adding a layer of complexity
to the fog potential is that we will have that band of mid/upper
clouds streaming south through the night that could really limit
radiational fog potential for the north bay. Other than the
potential for mid/upper clouds, Monday looks like another pleasant
weather day before more active weather finally makes a return.
&&
.LONG TERM...
Issued at 234 PM PST Sun Feb 8 2026
(Monday night through next Saturday)
For Tuesday into Wednesday, the GFS has followed the ECMWF in being
much stronger with the system that moves into the California coast,
with closed lows from the surface up to h5. This includes 30-40 kt
southerly jets at 925 and 850 mb that will crash into the Bay area
that will help push a stronger moisture surge into the area, with a
good wetting rain expected Tuesday afternoon into Tuesday evening.
Precip amounts continue to creep up with this event, with most lower
elevations forecast to get 0.5" to 0.75" of rain, with up to 1.5" of
rain in the high elevations of the Big Sur region. Surface troughing
will linger through Wednesday night, which will keep some light
rain/drizzle going in coastal mountains into early Thursday.
Thursday and Friday continue to trend dry as a ridge moves through
out ahead of our weekend trough that will be developing in the
northeast Pac. As for that weekend trough, there are timing
differences with when the firehose of moisture arrives, but whether
it arrives Saturday afternoon (GFS/GEFS) or Saturday night
(ECMWF/EPS), everything ends up in the same spot, a very wet end to
next weekend, with PoPs in excess of 80% already in place a week
out, indicative of this being a fairly predictable event. This will
just be the start of a wet pattern, with numerous rounds of rain
continuing through the following work week. As for snow potential,
we do see freezing levels come down this weekend, but from the
perspective of the MTR area, it's only the tops of our tallest peaks
that show some snow potential. Freezing levels look to take a
further step down next week (week of 2/16), which is when maybe we
could see freezing levels low enough to start getting into the MTR
mountains.
&&
.AVIATION...
(00Z TAFS)
Issued at 349 PM PST Sun Feb 8 2026
A weak front will move across the area tonight. A few light
showers will develop over the North Bay, but rain amounts will be
minimal. Additionally, marine stratus has moved into coastal
areas ahead of the front. Low stratus will push inland late this
afternoon and evening, bringing IFR/MVFR ceilings to most
terminals. As the main front moves through this evening and
overnight, low ceilings will continue, but should not be quite as
low as the activity late this afternoon. This should also reduce
any threat for fog development. Behind the front Monday morning,
winds will turn northerly, bringing in drier air. Conditions will
improve as a result with widespread VFR conditions returning.
Winds will mainly be light onshore/NW this evening, turning
northerly on Monday.
Vicinity of SFO...Marine stratus will continue to bring IFR
conditions through early evening, but should lift to MVFR by mid
evening (around 02-04Z) and continue overnight as the front
pushes through. Conditions will improve early Monday morning as
northerly winds bring in drier air and erode the stratus layer.
VFR conditions expected to prevail through the day Monday. Winds
WNW around 10 kts or less overnight, then light northerly on
Monday.
SFO Bridge Approach...Similar to SFO.
Vicinity of SJC and OAK...Marine stratus has pushed into OAK, and
will advance toward SJC this evening, arriving 02-04Z. Mainly MVFR
conditions, although brief IFR is possible. Improvement is
expected late tonight into early Monday morning (around 10-14Z) as
drier air is brought in by northerly winds and erodes the
stratus. Fog potential is lower tonight than previous nights.
Winds light W-NW this evening, becoming N-NW on Monday.
Monterey Bay Terminals...IFR/MVFR ceilings will persist over
MRY/SNS through the evening. Confidence on low ceilings decreases
overnight into Monday morning. By late Monday morning, conditions
will be VFR as stratus erodes. Winds will be light NW to variable.
&&
.MARINE...
(Tonight through next Friday)
Issued at 349 PM PST Sun Feb 8 2026
A cold front will move southeastward over the coastal waters and
bays tonight and early Monday. Seas will continue moderate today.
Northwest winds will strengthen to a fresh to strong breeze today
into Monday. A low pressure system will then approach from the
west bringing rain to the coastal waters and bays Tuesday through
Wednesday.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory until 9 PM PST Monday for Pt Pinos to Pt
Piedras Blancas 0-10 nm.
Small Craft Advisory from 9 PM this evening to 9 PM PST Monday
for Pt Arena to Pt Reyes 10-60 NM.
Small Craft Advisory from 9 PM this evening to 3 PM PST Monday
for Pigeon Pt to Pt Pinos 10-60 NM.
&&
$$
SHORT TERM...MPG
LONG TERM....MPG
AVIATION...Tangen
MARINE...Soulat
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Prepared by Boulder-Creek.com Weather at: Sun Feb 8 20:30:04 PST 2026
From the National Weather Service
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