textproduct: San Francisco Bay Area

KEY MESSAGES

Updated at 341 AM PST Sun Mar 1 2026

- Cooler today with very light rain returning to the North Bay and Pacific Coast later today, tonight and Monday morning

- Above normal temperatures with elevated winds and offshore flow mid to late week

- Potentially hazardous marine conditions late week

SHORT TERM

Issued at 449 AM PST Sun Mar 1 2026 (Today and tonight)

The SFO-SAC pressure gradient is 1.9 mb. Fresh onshore winds from the surface through the lower levels of the atmosphere continue to bring cooler air inland. Satellite shows areas of low clouds forming in the cooler air intrusion across the Bay Area and north Central Coast. Mid to high level clouds continue to move in from the southwest. 24 hour surface temperature trends are solidly cooler including across the higher elevations with widespread 50s and a few spots in the mid to upper 40s. 500 mb height ridging is to our east. A closed 500 mb low is ~ 500 miles west-northwest of San Francisco and it's forecast to move east across northern California tonight and Monday morning. Cooler air with the low will bring a chance of wet weather and a slight chance of thunderstorms mainly tonight and Monday morning.

LONG TERM

Issued at 449 AM PST Sun Mar 1 2026 (Monday through Saturday)

Light measurable precipitation chances from the North Bay to the San Francisco Peninsula, including part of the East Bay south to the Big Sur Coast Monday morning decrease by Monday afternoon. 500 mb height ridging arrives from the west Monday night and Tuesday. Cooler air with surface high pressure arrives Wednesday night and Thursday morning. From mid to late week surface high pressure over the eastern Pacific will steadily strengthen bringing our coastal waters gusty northwest winds with land overlap of gusty northwest winds. For Friday and Saturday recent ECMWF and GFS ensemble means forecast a 7 mb to 9 mb WMC-SFO pressure gradient supporting moderate offshore winds. Guidance shows 925 mb and 850 mb northerly to northeasterly winds increasing from mid to mostly late week. If this synoptic pattern verifies it would result in dry conditions and downsloping gusty winds to the coastline with the potential for larger diurnal temperature ranges from cool/chilly morning lows (if the valleys decouple from winds aloft) to ~ 10F above early March normal daytime highs to the mid to upper 70s if not Friday then Saturday perhaps on Sunday too.

AVIATION

(12Z TAFS) Issued at 438 AM PST Sun Mar 1 2026

Conditions vary from LIFR-IFR to VFR with areas of low clouds forming in a cooler air intrusion on onshore winds. Steady cool air advection up through 925 mb and 850 mb levels will continue to weaken the lower level temperature inversion today, tonight and Monday. A steady weakening of the temperature inversion, diurnal surface warming and mixing will allow better chances of VFR from late morning through the afternoon. Light measurable precipitation with MVFR to possibly IFR conditions develop tonight and Monday morning.

Vicinity of SFO...MVFR conditions to 16z then increasing mixing today improves conditions to VFR. Light drizzle with a mix of IFR and MVFR tonight and Monday morning. West wind near 10 knots.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...Low clouds /IFR/ lifting to MVFR by late morning. MVFR-IFR with areas of light drizzle developing tonight and Monday morning. Mainly onshore winds 5 to 10 knots.

MARINE

(Today through Friday) Issued at 348 AM PST Sun Mar 1 2026

A chance of showers and a slight chance of thunderstorms return late tonight into Monday morning mainly over the northern waters. Seas continue to abate until mid-week. However by late week, high pressure strengthening over the eastern Pacific will likely result in northwest winds to gale force and steepening seas over 12 feet.

MTR WATCHES/WARNINGS/ADVISORIES

CA...None. PZ...None.