textproduct: San Francisco Bay Area

KEY MESSAGES

Updated at 1232 PM PDT Tue Sep 22 2026

- Warming trend continues through Thursday

- Cooler conditions Friday into the weekend

SHORT TERM

Issued at 1103 PM PDT Tue Sep 22 2026 (Tonight through Thursday)

Marine layer between 1500-2000 feet deep as of Tuesday evening. Low clouds cover areas from Point Reyes southward to Big Sur with a decent push of stratus in SF Bay and the Monterey Bay region including Salinas valley. There is an increasing northerly gradient now to about 5 mb from ACV-SFO that is eroding the stratus from north to south for the North Bay. This is occurring as high pressure is trying to nose into the region from the southwest. 850 mb temps warming to around 20-21 celsius with hot inland temps for the interior Central Coast (90s) with mainly upper 80s to around 90 for the interior North/South/East Bays on Weds afternoon. With persistent onshore winds not really a late September setup where we would expect warm/hot temps at the coast. Looking at the European extreme forecast index we see no areas of interest suggesting this is just a typical warm late Sept day on tap. Models hold onto the warm inland temps for one more day through Thursday. However by Thursday afternoon a storm well to our north will induce a strong onshore/westerly push, ushering in a moderate to strong afternoon/evening seabreeze on Thursday that will signal relief for the Bay Area while the interior Central Coast remains warm/hot through Thursday evening.

LONG TERM

Issued at 1103 PM PDT Tue Sep 22 2026 (Thursday night through next Tuesday)

A fairly well defined early autumn dry cold front passage will push through the region Thursday night into Friday morning. No precip is forecast for the Bay Area as it remains confined to areas north of Cape Mendocino. However, enough cooling and mixing aloft to essentially erode or mix out the marine layer quickly by early Friday morning. Temps still remain seasonably warm/mild Friday but the cooling trend will have begun. Weather this weekend looks nice for the last weekend of September. Certainly no hot weather with inland temps mainly 70s to lower 80s Saturday/Sunday with enough cold air aloft and mixing to keep skies sunny with perhaps only some patchy morning low clouds near the coast and bays.

Early look at next week shows no signal for precip or abnormally hot weather and no fall offshore wind events. Pattern looks pretty zonal suggesting temps running near seasonal norms.

AVIATION

(12Z TAFS) Issued at 445 AM PDT Wed Sep 23 2026

Marine layer returned, but a tad more compressed this morning in the 1500-1800 foot range. As such, seeing more reduced vis with LIFR conditions for N Bay and Monterey Bay regions. Elsewhere IFR for SF Bay and VFR for S and E Bays. Expecting VFR this afternoon as N-S increases. Less CIGs expected tonight with drier airmass and strong pressure gradients, but conf is low for CIGs SF Bay.

Vicinity of SFO...Circulation inside SF Bay led to some clearing earlier in the night, but since then eddy weakened and stratus filled in for SFO with IFR CIGs. Will keep CIGs into the AM rush then VFR this afternoon. Low conf for CIGs tonight, but did include some CIGs late tonight.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...LIFR conditions will impact Monterey Bay areas through mid-late morning. VFR expected this afternoon. IFR to LIFR conditions return early this evening.

MARINE

(Today through Monday) Issued at 445 AM PDT Wed Sep 23 2026

Northerly breezes will ease early Wednesday near shore, but remain moderate to fresh over the outer waters. Locally hazardous conditions will persist for small craft over the outer waters through Wednesday night. Winds will weaken further across all waters on Thursday. Friday will see an increase in northwest winds accompanied by seas building back up to rough, and continuing into the weekend.

MTR WATCHES/WARNINGS/ADVISORIES

CA...None. PZ...Small Craft Advisory until 5 AM PDT early this morning for Pigeon Pt to Pt Pinos 10-60 NM-Pt Arena to Pt Reyes 0-10 nm.

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