textproduct: San Francisco Bay Area

KEY MESSAGES

Updated at 1036 PM PDT Tue May 19 2026

- Diurnally driven winds, with onshore winds during the afternoon and early evening.

- Above normal temperatures continue through midweek with seasonal temperatures returning late week.

- Warm and dry weather through Thursday leads to elevated fire weather concerns for the interior Bay Area and Central Coast.

SHORT TERM

Issued at 1036 PM PDT Tue May 19 2026 (Tonight through Thursday)

Little change in the forecast as high pressure slowly creeps into Northern California today. Satellite imagery this evening shows high clouds sliding down the West Coast, with much of the Bay Area likely seeing some cirrus. With the current data, temperatures look to be on track; however, if we're not able to get radiational cooling, our temperatures for tonight might be low/cool. This would be because the clouds act as blanket, allowing less heat to escape at night. It'll be something to keep an eye on over the next few hours.

In terms of Wednesday, if you guessed, "No pattern change. Ha, this means another day of warmer weather", you'd be correct! A potential fly in the ointment is if the marine layer attempts to manifest around 500 feet. This might keep temperatures a few degrees cooler along the immediate coast, but elsewhere temperatures should be similar to Tuesday, perhaps a few degrees higher.

LONG TERM

Issued at 1036 PM PDT Tue May 19 2026 (Thursday night through next Tuesday)

No major changes to the extended forecast. Upper level troughing looks to keep hold over the western US, while the Pacific high pushes even more into northern California on Thursday. With the high being a bit more pronounced, another warm day will be on tap. After that, guidance has flow becoming quasi-zonal for a brief period before troughing returns on Friday. The marine layer looks to be around 500ft on Thursday, deepening to around 1000ft by Friday and then lasting through the weekend. With onshore flow, a deeper marine layer, and troughing through the weekend the NBM's temperatures are bit too warm. Opted to start trending towards slightly cooler temperatures given the ensembles and cluster analysis. But there is a chance ridging wins out and temperatures might warmer. Definitely something to keep an eye on over the next few days.

AVIATION

(06Z TAFS) Issued at 926 PM PDT Tue May 19 2026

Currently VFR at all terminals with the exception of MVFR at HAF. Winds may become calm and/or light and variable overnight. Low to moderate confidence in IFR conditions developing at terminals tonight - the most likely timeframe is 12Z to 16Z. Coastal terminals will be at greatest risk with risk decreasing for bayshore and interior terminals, respectively. Higher confidence in IFR conditions returning tomorrow night.

Vicinity of SFO...Currently VFR with northwesterly flow. Moderate to high confidence in VFR and diurnal winds prevailing through the TAF period. Low probability for sub-VFR conditions to develop at the terminal tonight as the compressed marine layer will be unable to penetrate the San Bruno Gap. Reasonable worst case scenario is stratus sneaks through the Golden Gate Gap and brings FEW/SCT to the north side of the terminal.

SFO Bridge Approach...The San Mateo Bridge Approach has a lower probability of sub-VFR conditions.

Monterey Bay Terminals...Currently VFR and calm at MRY and VFR with northerly flow at SNS. Confidence has increased in sub-VFR conditions developing at the terminals tonight, especially for MRY. Ceilings will likely be on the cusp of IFR/LIFR.

MARINE

(Tonight through next Monday) Issued at 926 PM PDT Tue May 19 2026

Hazardous conditions for small craft will continue through Wednesday for the northern outers due to rough seas and strong northerly breezes. Elsewhere, moderate to fresh northwesterly breezes and moderate seas will prevail. Conditions improve into the weekend as seas and northwesterly breezes become moderate.

MTR WATCHES/WARNINGS/ADVISORIES

CA...None. PZ...Small Craft Advisory until 3 PM PDT Thursday for Pt Arena to Pt Reyes 10-60 NM.