textproduct: San Francisco Bay Area

KEY MESSAGES

Updated at 1026 PM PDT Mon May 18 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

SHORT TERM

Issued at 1026 PM PDT Mon May 18 2026 (Tonight through Tuesday)

The forecast appears to be on track, with broad upper level troughing holding over much of the western U.S. while high pressure builds over the eastern Pacific. The good news, is that our breezy offshore winds have eased substantially leaving us with fairly calm weather in return. Tonight, skies will remain clear and temperatures will generally fall into the 50s for the valleys, perhaps upper 40s for some coastal sites and the southern Salinas Valley. At higher elevations, a thermal belt will exist as temperatures fall into the mid 50s to low 60s and may still have some northerly winds. For those in the valleys, winds will generally be light and variable.

Tomorrow, another warm day will be on tap. The question will be, how do the temperatures pan out? Offshore flow won't be as prevalent, which means there could be less of a downsloping / warming of the air affect. But, that upper level high slowly creeps towards us and the marine layer is essentially negligible. Opted to blend a bit of the observations from Monday to the NBM giving us a similar forecast, to what occurred yesterday. The interior Bay Area valleys should make it into the 80s, perhaps near 90 degrees, while coastal communities experience a tighter gradient of highs in the 60s to low 70s. The San Francisco Peninsula should be similar, with the Pacific side having temps range from the mid 60s to low 70s, while the Bay side ranges from the upper 70s to mid 80s. And finally the Central Coast, interior locations rise into the mid 70s to mid 80s, while coastal communities vary from the mid 60s to the low 80s.

LONG TERM

Issued at 1026 PM PDT Mon May 18 2026 (Tuesday night through next Monday)

No major changes to the extended forecast. Upper level troughing looks to keep hold over the western US through at least Wednesday, with that Pacific high slowly peeking into northern CA. This should bring a return of onshore flow to the region and eventually the marine layer. Warm weather looks to linger through at least Wednesday, with Thursday potentially seeing a slight change in temperatures if the marine layer develops. Guidance for Thursday caps it at 500ft at best, with the marine layer getting to 1000ft by Friday. The marine layer appears to better establish itself Friday night into Saturday, likely getting to around 1000ft again. Will need to keep an eye on this as it will affect how temperatures pan

AVIATION

(12Z TAFS) Issued at 436 AM PDT Tue May 19 2026

VFR through the forecast period. There is a 15-25% chc of seeing MVFR CIGs by the very end of the TAF period. Not high enough confidence to include in TAF just yet. Breezy onshore flow expected again this afternoon.

Vicinity of SFO...VFR. Light NE flow expected this AM then switch onshore this afternoon with gust up to 20 kt.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...VFR. Hedging toward the 20-25% for some CIGs developing by 12Z Wednesday.

MARINE

(Today through Sunday) Issued at 436 AM PDT Tue May 19 2026

The overall sea state continues to improve with decreasing winds and seas. Fresh northerly breezes will persist over the outer waters north of Pigeon Point leading to hazardous conditions through at least Wednesday night.

MTR WATCHES/WARNINGS/ADVISORIES

CA...None. PZ...Small Craft Advisory until 9 AM PDT this morning for Pigeon Pt to Pt Pinos 10-60 NM-Pt Arena to Pt Reyes 0-10 nm-Pt Reyes to Pigeon Pt 0-10 nm.

Small Craft Advisory until 9 PM PDT Wednesday for Pt Arena to Pt Reyes 10-60 NM.