, Issued at 213 PM PST Thu Jan 22 2026 (This evening through Friday)
The closed low that brought showers to the area last night and this morning is spinning further away to the south. An inside tracking low pressure system (inside slider) will quickly dig into Nevada late Friday. As a result, temperatures will not recover and remain around normal, some issues will continue, and north to northeast winds will start to develop.
For the low clouds and fog, coverage should be fairly similar to this morning, with the north hills, southern Bay Area, and Monterey areas likely to see some. Visibilities could drop to below 1 mile in some spots.
For the winds, speeds will be fairly light through mid-day Friday, then northerly winds will start to pick up. By Friday evening, gusts of 25 to 35 mph will develop mainly over the interior mountains of the North Bay area. The winds will turn northeasterly and spread by early Saturday (see long term section).
..issued at 213 PM PST Thu Jan 22 2026 (Friday night through next Wednesday)
As the cold air from the insider slider settles into Idaho and Nevada on Saturday, the offshore leaning surface pressure gradients will strengthen. The winds aloft will also become offshore from the surface through and above 10,000 feet, resulting in a deep layer of 25 to 35 knot flow. The combination of this surface pattern and moderate upper level support will allow the winds at the ground to shift to north to northeasterly and expand on Saturday, then persist into Sunday. The winds will affect much of the wind prone areas, but be focused over the northern mountains and hills where wind gusts of 25 to 35 mph will be common, and isolated gusts of 45 mph are possible. The air will also get very dry, but fire weather concerns are low due to the state of the fuels.
The offshore flow will shut down by Monday as weak ridging aloft will bring fairly quiet conditions into Tuesday. Some low clouds and fog will likely form over the coastal areas as the marine layer reestablishes itself.
Then big question marks start to pop up after that. About half of the ensemble projections show a rain making cold front moving down the coast around Wednesday or Thursday, with some gusty south winds. The other half do not. If it does rain, the amounts will be light as none of the individual runs have anything over an inch.
(00z TAFS) Issued at 332 PM PST Thu Jan 22 2026
The big story for the aviation forecast is the potential for fog formation overnight. Current dew points are in the mid to upper 40s across the San Francisco Bay Area, and low 50s across the Monterey Bay area. This is a few degrees higher than yesterday, but the temperature are anywhere from 5-15 degrees warmer so the RH is actually lower across the board. However, the clearing skies will allow for enhanced radiational cooling in the valleys. The effect will be bolstered by the return of onshore winds and the reintroduction of a cool, moist marine influenced air mass near the coast and adjacent valleys.
Vicinity of SFO, The marine layer is expected to be around 1,000 feet deep when the onshore flow returns throughout the boundary layer this evening. That's deep enough to spill over San Bruno Mountain and impact the terminal. It's unclear if this will be in the form of ceilings, fog, both, or neither. The most likely outcome is IFR ceilings through the morning hours, but there is still a lot of uncertainty until the winds flip to onshore and clouds start to fill the coastal waters.
SFO Bridge Approach, Similar to SFO.
Monterey Bay Terminals, Marine layer impacts are expected at both MRY and SNS Thursday night through Friday morning, with higher confidence than the northern terminals due to the higher dew points.
(tonight through next Tuesday) Issued at 113 PM PST Thu Jan 22 2026
North winds and choppy seas will steadily increase through Friday over the region, strongest over the northern outer waters. Small Craft Advisories are already posted, with a 30 percent chance of localized Gale Force winds over the outer waters off Point Arena on Friday. Seas and winds will gradually ease Saturday afternoon and remain around typical into the beginning of next week. Steep seas and gusty south winds possible around mid-week with a storm system.
Ca, None. PZ, Small Craft Advisory until 3 AM PST Saturday for Pt Arena to Pt Reyes 10-60 NM.
