textproduct: San Francisco Bay Area

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.