textproduct: San Francisco Bay Area

KEY MESSAGES

Updated at 925 PM PDT Sat Sep 19 2026

- Brief cooling Sunday through Monday

- More substantial warming trend Tuesday through Thursday

SHORT TERM

Issued at 925 PM PDT Sat Sep 19 2026 (Tonight through Monday night)

Residual polar jet stream winds will merge with the subtropical jet stream at the base of a weak 500 mb low currently ~ 500 miles west of Monterey and move the low eastward across our forecast area later Sunday through Monday. Cool onshore breezes will help keep temperatures below normal. Daytime highs Sunday will be cooler than typical for Sep 20th with highs in the 60s coastside/bayside to the 70s and 80s inland. Highs Monday will be about the same as on Sunday. A few patches of late night and morning light drizzle may form in the cooled air near surface to aloft.

LONG TERM

Issued at 925 PM PDT Sat Sep 19 2026 (Tuesday through next Saturday)

500 mb low amplitude ridging will develop Tuesday into early Thursday. This will bring a warming trend here during these three days, which will help push daytime highs up to the 90s/100 inland Wed-Thu (cooler at the coastline and bays). The pattern across the North Pacific to the western CONUS is progressive, which lowers confidence a little in the timing of 500 mb ridging residence time and this may influence the duration of warm/hot weather currently forecast for mid next week. Stay tuned to the latest updates.

AVIATION

(06Z TAFS) Issued at 921 PM PDT Sat Sep 19 2026

VFR prevails except for coastal stratus and mist/fog /IFR/. Onshore winds will bring stratus and mist/fog /IFR-LIFR/ inland tonight and Sunday morning. Conditions improve to MVFR-VFR near the coastline Sunday afternoon while VFR continues farthest inland. Stratus and mist/fog /IFR-LIFR/ return inland Sunday night and early Monday morning.

Vicinity of SFO...VFR and a west wind near 15 knots during the evening, west wind then diminishing to near 10 knots tonight and Sunday morning. MVFR stratus ceiling forecast 07z-19z Sunday. Stratus /MVFR/ redevelops Sunday evening and night. West wind 10 to 15 knots Sunday afternoon and evening.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...Stratus and mist/fog /IFR-LIFR/ are nearby and will move inland tonight and Sunday morning. Conditions improve to MVFR-VFR by late Sunday morning and afternoon. Stratus /IFR-LIFR/ redevelops Sunday night. Mainly onshore winds 5 to 15 knots.

MARINE

(Tonight through next Thursday) Issued at 828 PM PDT Sat Sep 19 2026

Moderate northwest winds will continue tonight into Sunday then increase Sunday afternoon and evening as a weak upper low approaches the region. Fresh wind wave seas will continue over a long period southerly swell. High pressure builds Tuesday through Thursday with winds easing near shore.

FIRE WEATHER

Issued at 1229 PM PDT Sat Sep 19 2026

The marine layer is around 1,500 feet deep and compressing. There were some offshore winds this morning, but the sea breeze is taking over as the offshore gradient relaxes. Today will be warmer and slightly drier than recent days, although winds will be lighter through the peak burn period. Cooler and more humid conditions arrive Sunday-Monday before a longer warming trend Tuesday through Thursday.

MTR WATCHES/WARNINGS/ADVISORIES

CA...None. PZ...Small Craft Advisory until 9 AM PDT Sunday for Pt Arena to Pt Reyes 0-10 nm.

Small Craft Advisory until 3 AM PDT Sunday for Pigeon Pt to Pt Pinos 0-10 nm.

Small Craft Advisory from 3 PM to 9 PM PDT Sunday for Pigeon Pt to Pt Pinos 0-10 nm.

Small Craft Advisory until 3 AM PDT Monday for Pigeon Pt to Pt Pinos 10-60 NM-Pt Pinos to Pt Piedras Blancas 0-10 nm.

Small Craft Advisory until 9 AM PDT Monday for Pt Arena to Pt Reyes 10-60 NM.