FXUS66 KMTR 232011
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
1211 PM PST Fri Jan 23 2026

...New SHORT TERM, LONG TERM...

.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...
(18Z TAFS)
Issued at 956 AM PST Fri Jan 23 2026

Satellite imagery shows almost all of the Bay Area and 
Central Coast socked in with fog and stratus, unless your over 3000 
or 4000ft elevation. The question for today becomes, will we be able 
to mix out? Model guidance has not been the greatest with many 
showing clearing happening around 18Z. MOS guidance might be the 
most pessimistic, with some sites potentially being locked in 
through the day. Opted to trend more pessimistic given the spread of 
this and the lack of clearing. Should this tule fog and stratus 
stick around, expect MVFR to IFR cigs at the terminals through the 
period. If we're able to mix out and get winds a little breezier, we 
may get some VFR conditions for a few hours. 

Tonight, the forecast is difficult once again. Opted to go 
pessimistic for most TAF sites as well given models have struggled 
this morning. Look for another night of MVFR to LIFR conditions.

Vicinity of SFO...Moderate to low confidence in the SFO forecast. 
Opted to trend with cigs clearing later this afternoon and then 
staying VFR through the period. Given most guidance has low clouds 
flirting around SFO, opted to keep the mention of FEW015 and SCT010 
in the forecast. Some guidance shows 20-40% chance of BKN MVFR cigs 
overnight, with cigs eroding shortly after sunrise. Will need to 
keep an eye on the overall forecast given the current cloud deck 
over the region. 

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...MVFR to IFR cigs are being observed this 
morning and these should remain locked in through the period. We 
should see a brief period of onshore winds this afternoon, otherwise 
winds look to be light and variable. 

&&

.MARINE...
(Today through Wednesday)
Issued at 841 AM 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/Murdock
AVIATION...KR
MARINE...KR

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Prepared by Boulder-Creek.com Weather at: Fri Jan 23 12:30:03 PST 2026