textproduct: San Francisco Bay Area

KEY MESSAGES

Updated at 1242 PM PDT Tue May 26 2026

- Cooler, unsettled weather conditions continue today and Thursday

- Warming and drying trend Friday and beyond

SHORT TERM

Issued at 1151 PM PDT Tue May 26 2026 (Today and tonight)

The center of the upper level disturbance responsible for the cool and unsettled weather yesterday and today will remain mostly stationary throughout the day. However it will weaken slightly over the course of the day with subtle H50 height increases from early this morning into this evening. The unusually cool air aloft, once again looking at H50 level, will be below the tenth percentile at around -21C to -22C, with H85 temps right around the tenth percentile at 5C to 6C. The cooler than normal temperatures aloft are transferring to the surface with low lying interior locations running 5F-10F degrees below normal for this time of year, and much cooler than normal at higher elevations, especially the highest peaks of Big Sur around 25F-30F degrees below normal.

As the upper low rotates overhead today, portions of the Bay Area, East Bay and South Bay will see periods of sunshine helping to produce marginal surface instability from around 100-300 J/Kg of CAPE this afternoon. Vertical wind profiles don't favor organized convection, with little to no 0-6km wind shear. Like yesterday in Napa County and Contra Costa County the best chances for rainfall amounts above 0.10" will be areas of terrain enhancement. The hills of eastern Contra Costa County and eastern Santa Clara County have approximately 20%-50% chance of exceeding 0.10" by late this afternoon. NBM thunderstorm chances are less than 10% area wide.

A portion of the upper level low will begin to retrograde back toward the coast tonight into early Thursday morning, increasing rain chances off shore that eventually begin to move onshore along the coast late tonight and farther inland through Thursday morning. Rain totals along the coast late tonight into early Thursday morning will be light, primarily less than a 0.10" from Santa Cruz south down the Big Sur coastline.

LONG TERM

Issued at 1151 PM PDT Tue May 26 2026 (Thursday through Tuesday)

Thursday will continue the unsettled pattern with a shift south across primarily the South Bay and Central Coast as the upper low begins to shift inland to the southeast during the day Thursday. The clouds and cooler temperatures will linger during the day Thursday with only light rainfall amounts where rain does occur, with less than a 0.10" expected.

Progressive upper ridging behind the exiting low to the east on Friday gives way to zonal flow aloft on Saturday as temperatures begin to rebound back closer to normal by Sunday into the beginning of next week. While we do gradually warm up through the remainder of the extended forecast beginning Friday, a signal for troughing in the syntopic pattern continues beyond the current extended forecast that should help maintain more seasonal temperatures.

AVIATION

(06Z TAFS) Issued at 959 PM PDT Tue May 26 2026

Primarily VFR conditions tonight outside of coastal areas. Guidance suggests some potential for MVFR CIGs to impact interior Bay Area airports tonight but confidence is on the lower end. High resolution guidance shows RH values around 80-90% in the lower levels of the atmosphere. This supports at least few to scattered low level clouds but not confident on BKN/OVC conditions. LAMP guidance shows a low chance for MVFR CIGs and leans towards keeping into sites VFR overnight. Winds are easing across the region but will remain locally gusty overnight. The SFO-WMC gradient will be weaker on Wednesday than it was on Tuesday but it will still be around -10 to - 12 mb at its afternoon peak. This supports another round of gusty winds tomorrow although gusts peak around 20-25 knots instead of 30- 35 knots today. Widespread showers return towards the end of this TAF period and continue into the rest of tomorrow night.

Vicinity of SFO...VFR through the TAF period. Not anticipating low clouds to develop at SFO tonight with CIGs staying above 3000 ft. Gusty westerly winds will diminish overnight before another round of breezy winds tomorrow afternoon/evening. Tomorrow's winds will be weaker with gusts peaking around 25 knots. Scattered showers approach SFO after 06Z tomorrow with shower chances increasing further around 12Z.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...MVFR CIGs continue through 17/19Z with VFR the rest of the day. Westerly winds are diminishing at MRY and SNS with winds to ease further overnight. Winds restrengthen during the afternoon/evening when gusts to around 20 knots are expected. Scattered showers are possible in the vicinity of MRY tonight with shower chances becoming more widespread (impacting both MRY and SNS) tomorrow night.

MARINE

(Tonight through next Monday) Issued at 916 PM PDT Tue May 26 2026

Fresh to strong northwest winds continue tonight with winds gradually diminishing across the inner waters heading into tomorrow. Occasional near gale to gale force gusts are possible across the far outer waters through Wednesday afternoon. Rough seas continue with wave heights between 12 to 16 feet through Thursday.

MTR WATCHES/WARNINGS/ADVISORIES

CA...Beach Hazards Statement until 9 AM PDT Wednesday for CAZ006-505- 509-529-530.

PZ...Small Craft Advisory until 3 AM PDT Wednesday for Mry Bay-Pigeon Pt to Pt Pinos 0-10 nm-Pt Reyes to Pigeon Pt 0-10 nm-SF Bay N of Bay Bridge.

Small Craft Advisory until 9 AM PDT Wednesday for Pt Arena to Pt Reyes 0-10 nm.

Gale Warning until 3 AM PDT Wednesday for Pt Pinos to Pt Piedras Blancas 0-10 nm.

Small Craft Advisory until 3 PM PDT Thursday for Pt Arena to Pt Reyes 10-60 NM.

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