textproduct: San Francisco Bay Area

KEY MESSAGES

Updated at 1201 PM PDT Sat May 2 2026

- Cooler temperatures through the early part of this week with a chance for drizzle and light rain, mainly along the coast

- Widespread stratus persists overnight and into the morning through Sunday

- Warmer and drier conditions return for the middle of the week

SHORT TERM

Issued at 201 AM PDT Sun May 3 2026 (Today and tonight)

Onshore winds continue to carry clouds and cooler air farther inland. 24 hour trends show cooler to much cooler air is reaching the higher elevations of the forecast area as well. Temperatures vary from the 50s to the 40s at 1 am. A cloudy, chilly start and continuation of cool air advection will slow the diurnal warming process today. There may be spotty light drizzle. Forecast highs are in the 60s today though it may be difficult to break out of the 50s along the immediate coastline. The best chance of the sun breaking through the clouds will be farthest inland from late morning through afternoon. Onshore winds, low clouds and chilly temperatures prevail tonight. A few additional patches of light drizzle are possible.

LONG TERM

Issued at 201 AM PDT Sun May 3 2026 (Monday through Saturday)

Residual polar jet stream winds on the back side of the 500 mb closed low currently to our west will have already merged with subtropical jet stream winds by Monday. By Monday the center of the 500 mb low is forecast to be located over the Central Coast to the Sierra Nevada/westernmost NV. The forecast gets a little more challenging later Monday and early Tuesday with respect to wet weather potential over our forecast area. Our current official forecast carries light rain (0.10" or less) developing over the North Bay and the East Bay and dry elsewhere during this time. However, something to keep in mind is recent output e.g. from the ECMWF/GFS/NAM show greater measurable rain later Monday and early Tuesday. Lingering cold air aloft, with the 500 mb low cold core, including possibly temporarily surface cooled air i.e. higher surface pressures locked over the highly varied terrain of CA while the mechanism for rainfall in this case becomes warm air advection at ~ 850 mb to 700 mb (up to ~ 10K feet up) arrives from the north and interacts with the colder air. At this time per model forecasts it's forecast as stratiform precipitation vs convective/unstable. Precipitable water is still forecast to peak 0.90" to 1" during this time. If the wetter pattern does develop, it'd bring more widespread beneficial light to moderate rain across more of our forecast area. Stay tuned to further updates.

From mid to late week high pressure aloft moves in from the west and northwest. Compressional warming within the high will steepen 850 mb temperatures well above normal and likewise with the help of the May sun angle, surface temperatures will warm well above normal for early May. A quick check on forecast 850 mb temps on the ECMWF show readings nearing the 90th percentile on Oakland upper air sounding climatology for the time of year. Daytime surface high temperatures far from any cooler maritime influences will climb to the 80s to lower 90s by late in the week.

AVIATION

(06Z TAFS) Issued at 934 PM PDT Sat May 2 2026

High clouds are now obscuring low clouds around the region. However, enough terminals and webcams continue to advertise MVFR CIGs. Current taf package will keep MVFR CIGs well into Sunday afternoon. Late Sunday afternoon and Sunday night confidence decrease as the marine layer becomes less pronounced and begins to mix. That being said, hard to bet against stratus already there and HREF does show some clouds reforming. Breezy onshore flow will return again Sunday afternoon.

Vicinity of SFO...MVFR CIGs through the Sunday AM rush. VFR and gusts 20-25kt Sunday afternoon. MVFR CIGs return Sunday night.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...MVFR CIGs for much of Sunday. Small window late Sunday afternoon where some SCT could occur.

MARINE

(Tonight through next Friday) Issued at 934 PM PDT Sat May 2 2026

High pressure to the north will maintain moderate to fresh northerly breezes through early Sunday morning. Seas will also subside on Sunday as winds continue to diminish. Moderate seas and a gentle to moderate NW breeze prevail Sunday into the early work week. Winds will gradually increase throughout the remainder of the work week.

BEACHES

Issued at 1201 PM PDT Sat May 2 2026

Long period northwest swell, with periods of 15 seconds or above, is expected to arrive along the Pacific coast today. These long period swells increase the risk of sneaker waves and rip currents, particularly as the period between swell impulses results in lulls of around 20 to 30 minutes before larger sets of waves arrive. Due to the dangers, a Beach Hazards Statement for all Pacific coast beaches comes into effect at 11 AM today and remains in effect until 11 PM Sunday night. Never turn your back to the ocean! Don't be fooled by calmer seas; observe the waves for at least 20 minutes before approaching the coast.

MTR WATCHES/WARNINGS/ADVISORIES

CA...Beach Hazards Statement through this evening for CAZ006-505-509- 529-530.

PZ...None.