FXUS66 KMTR 232350
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
350 PM PST Fri Jan 23 2026
...New AVIATION, MARINE...
.KEY MESSAGES...
Updated at 1209 PM PST Fri Jan 23 2026
- Gusty offshore winds across higher terrain of the North Bay and
East Bay Friday night through Sunday morning
- Morning fog across some Bay Area Valleys
- Potential weak storm system in the middle of the next work week
&&
.SHORT TERM...
Issued at 1209 PM PST Fri Jan 23 2026
(This evening through Saturday)
Low clouds linger across much of the lower elevations across the
region this afternoon as the return of a ~1500 ft marine layer
returned overnight. In addition, tule fog from the Central Valley as
pushed westward into the East Bay Valleys. By mid afternoon, mostly
sunny sky conditions are forecast expect for locations near the
coast where the marine layer persists.
Expecting offshore winds to develop across the higher elevations of
the North and East Bay valleys tonight and persist into Saturday.
Localized gust may exceed 50 mph in some of the peaks across the
region. This will dry things out considerably in these areas which
may also mix down into the valleys on Saturday. However, winds are
not forecast to be strong in the lower elevations. Afternoon
humidity values are likely to fall below 20% in the higher terrain.
Saturday, we are expecting offshore winds to persist in the higher
terrain. This offshore flow will work to compress the marine layer
and essentially completely mixing it out. Thus, a slight warm up in
temperatures can be expected with low to mid 60s for much of the
region.
&&
.LONG TERM...
Issued at 1209 PM PST Fri Jan 23 2026
(Saturday night through next Thursday)
Offshore winds look to diminish Saturday night into Sunday morning,
yet will still be moderate in the higher terrain. Therefore, low
clouds cover and/or fog will have a difficult time developing early
Sunday morning with continued offshore flow aloft. However, high
clouds will will begin to spread in from the west by that time.
From the previous forecaster: "The ridge looks to flatten into
Sunday evening, with a zonal jetstream pattern taking its place, and
offering more onshore flow. However the jetstream looks to snap back
to a quick ridge into the next work week. This means temperatures
will and some bounces up and down by a few degrees, and low cloud
formation will be spotty.
Despite the quick ridge development, high clouds look to move
through the region as a trough develops to the west. The trough
formation is well-argeed upon between the longer term models, but
the trajectory is a matter of debate. More models point to a cold
front, and maybe a weak low pushing through the area, bringing good
chances for widespread moderate rains by the mid week. However, the
GFS and its ensemble members seem keen on this trough getting pushed
up against the ridge ahead of it, and placing all the moisture well
to the north. The GFS output looks a bit less firm than other models
and the national blend, but is something to keep in mind as the
longer term models update. For now, the official forecast places
rain chances in the middle of the next work week along the initial
front with additional chances possible beyond the forecast
period."
&&
.AVIATION...
(00Z TAFS)
Issued at 350 PM PST Fri Jan 23 2026
Stratus is much more progressive on satellite than was initially
expected so have opted for much more pessimistic 00Z TAFs. Pulled
out clearing for STS and APC - APC may briefly clear this evening
but this will be temporary before stratus rebuilds in. Opted to push
the arrival of fog earlier with dense fog possible at STS and LVK.
Ceilings should rapidly clear out by 14-18Z as moderate offshore
winds develop across the region. Breezier afternoon conditions are
expected tomorrow with most sites expected to be between 10-15 knots.
Vicinity of SFO...VFR. Confidence is low that stratus will impact
SFO tonight with LAMP guidance showing a "chance" (less than 40%) of
stratus developing from 07-11Z. HREF guidance does not clearly show
stratus impacting SFO either so have opted to maintain SCT in the
TAF but not adjust to overcast conditions quite yet. IF any stratus
is able to develop it is likely to clear by 15Z due to the more
moderate offshore flow set to develop.
SFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...MVFR. Moderate to high confidence that MVFR
CIGs will persist through at least 15Z. Kept the clearing time for
MRY closer to 17Z but it could clear as early as 14/15Z. Winds shift
southeasterly overnight before switching onshore again during the
daytime/evening hours.
&&
.MARINE...
(Tonight through next Wednesday)
Issued at 350 PM PST Fri Jan 23 2026
Fresh to strong northerly breezes will prevail today with near
gale force gusts in the northwest waters. Elsewhere, gentle to
fresh northerly winds prevail. Seas will build to 8-12 feet
across exposed waters today through early Saturday. Conditions
will improve this weekend with a gentle breeze and moderate seas.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory until 3 AM PST Saturday for Pt Arena to Pt
Reyes 10-60 NM.
&&
$$
SHORT TERM...RGass
LONG TERM....RGass
AVIATION...Kennedy
MARINE...KR
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Prepared by Boulder-Creek.com Weather at: Fri Jan 23 20:30:03 PST 2026
From the National Weather Service
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