textproduct: San Francisco Bay Area

KEY MESSAGES

Updated at 1004 PM PDT Tue Apr 21 2026

- Cool conditions Wednesday with lingering showers through the morning

- Seasonal temperatures and dry conditions arrive Thursday

- Monitoring potential rain and drizzle this weekend into the early part of next week

SHORT TERM

Issued at 1004 PM PDT Tue Apr 21 2026 (Tonight through Thursday)

It was a pretty active day on Tuesday with quite a bit of lightning reported across the Bay Area and Central Coast, and a funnel cloud reported near Fremont. The chances for convection have basically shut down as with the lack of solar heating, and while lingering isolated showers are possible through the rest of the morning, not expecting convection to be an issue through Wednesday. Beyond the lingering showers, skies will be generally clearing Wednesday morning with mostly sunny conditions and a gentle onshore breeze developing by the afternoon hours. Low temperatures this morning range from the upper 30s to the middle 40s in the inland valleys, to the upper 40s and lower 50s near the coast and the Bays. High temperatures on Wednesday are close to the upper 50s to the middle 60s in the lower elevations, with a slight warming gradient towards the inland valleys, and the upper 40s to middle 50s at the higher elevations.

LONG TERM

Issued at 1004 PM PDT Tue Apr 21 2026 (Thursday night through next Tuesday)

Temperatures will warm slightly for Thursday and Friday as a barely noticeable ridge sets up over the region, with highs in the lower elevations range from the lower 60s to lower 70s, close to or slightly below the seasonal averages. Into the weekend, another trough will come into the region and cause temperatures to dip again, introducing slight chances for light rain and drizzle that are expected to continue through the middle of next week. The latest CPC outlook leans towards precipitation totals above the seasonal averages heading into the first week of May, with the note that this late into the spring, the daily seasonal average rainfall at downtown San Francisco falls around two or three hundredths of an inch.

AVIATION

(06Z TAFS) Issued at 1004 PM PDT Tue Apr 21 2026

Mid to high level clouds are expected through the night and into Wednesday, with spotty and inconsistent low clouds possible. Showers will linger into the night, but chances will continue to decrease until the early morning where another wave of showers moves along/adjacent to the low pressure center. As these morning showers move through, expect multiple shifts in winds specifically around the SF Bay. Rain rates will lead to modest reductions in visibilities from this wave of rain. These showers exit into the afternoon as moderate westerly winds build and skies begin to clear. Winds weaken into Wednesday night, becoming light and variable in the inland areas, while sites near the ocean see more northerly winds.

Vicinity of SFO...Spotty, non-impactful showers are beginning to dissipate. Mid-level clouds linger across the area into the night with west winds turning more southwest as the low center arrives. Shower activity returns as the low center focuses over the SF Bay into Wednesday morning, and the winds will become shifty and variable. Showers exit into early afternoon as winds turn southwest, then west-northwest for the late afternoon. Winds will ease into Wednesday night and turn northwest.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...Despite the unsettled weather, KMRY and KSNS should mainly expect VFR conditions this TAF period with a brief period of MVFR conditions brought on by passing rain showers. The rain Wednesday morning should remain light and will cause CIGs to lower. After the last shower passes through however, the cloud bases will begin to lift. The onset of the rain is an estimation, therefore there is a possibility it may begin slightly earlier or later. This will be updated as needed.

MARINE

(Tonight through next Monday) Issued at 1004 PM PDT Tue Apr 21 2026

Light pop-up showers are moving through the waters, but offer little impacts. Additional showers will be possible into Wednesday morning but these chances erode into that afternoon. As the weather breaks on Wednesday, winds will shift to a moderate NW breeze, before increasing to a fresh breeze on Thursday. Winds and seas ease into the weekend.

MTR WATCHES/WARNINGS/ADVISORIES

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