textproduct: San Francisco Bay Area

KEY MESSAGES

Updated at 0103 AM PDT Wed Oct 7 2026

- Hazardous heat inland persists through Thursday, never leave children or pets in unattended vehicles!

- Elevated fire weather conditions persist in the interior through Thursday

- Coastal flooding concerns due to astronomical tides and thermal expansion through the weekend

- Hazardous beach conditions along Pacific coastline later this week into the weekend due to long period swell

SHORT TERM

Issued at 103 AM PDT Wed Oct 7 2026 (Today and tonight)

The marine layer remains shallow and compressed tonight with only inland intrusion on satellite over the Monterey Bay into the Salinas Valley. KHAF is reporting 1/4mi vis in fog, KOAR is reporting 1/2mi and KMRY is down to a mile vis, thus can't rule out another Dense Fog Advisory along the Pacific Coast at some point over the remainder of the overnight into Wednesday morning.

The Heat Advisory remains in effect with high pressure still draped over our area, however later tonight, a weak upper level disturbance begins to encroach on the ridging pattern as it moves east today. Marginally improved onshore flow will bring more stratus into the North Bay and Bay Area later tonight than we've seen the past few nights, with the potential for more widespread impacts from fog possible into Thursday morning.

LONG TERM

Issued at 103 AM PDT Wed Oct 7 2026 (Thursday through Tuesday)

Although the aforementioned weak upper level disturbance will help break down the ridge it won't ultimately make it to the coast, instead it will be pulled south into a merger with the remnants of Rachel by the weekend. The hot temperatures will linger Thursday with no changes anticipated for the Heat Advisory to come to an end Thursday night.

The cooler temperatures through the weekend will be welcomed as temps return to more seasonal averages. An interesting synoptic pattern begins to unfold by Sunday into the beginning of next week. A series of mergers is set in motion, beginning with Rachel moving onshore. The Polar Jet trough absorbs the remnants of Rachel while moving entirely over our area (was farther east in prior deterministic output) with increasing confidence in scattered light rain, especially for the Central Coast Sunday night into Monday. While the upper level low producing our rainfall begins its shift east it will then merge with 'Disturbance 1' as it moves into the Desert Southwest. The upper level low impacting us this weekend will bring gusty winds into our typical valleys, gaps and passes with very strong winds possible above 50 MPH for elevated portions of the East Bay both Friday night and Saturday night.

AVIATION

(12Z TAFS) Issued at 410 AM PDT Wed Oct 7 2026

Currently LIFR-VFR. Dense fog has been observed at the coastal terminals of HAF, MRY, and SNS overnight; however, an eddy has pulled it away from the Monterey Bay terminals. As such, TEMPOs remain in place for dense fog at MRY and SNS through 16Z with it prevailing at HAF through 17Z. Persistence forecast on tap tonight with a compressed marine layer keeping bayshore and interior terminals VFR while LIFR returns early to the coastal terminals. Diurnal winds will prevail.

Vicinity of SFO...Currently VFR with westerly flow. High confidence in VFR and diurnal winds prevailing through the TAF period.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...Currently VFR and calm at both terminals. An eddy has peeled dense fog back to the immediate coast, leading to VFR at the terminals. With the close proximity, have opted to go TEMPO in case it's able to remain on the edge and/or push back in. High confidence in VFR by 18Z; however, reasonable best case scenario is it'll be closer to 16Z or even earlier based on persistence, current trends, and the shallow nature of the marine layer. Persistence forecast on tap tonight with an early return of LIFR ceilings by 03Z. Diurnal winds will prevail.

MARINE

(Today through Monday) Issued at 410 AM PDT Wed Oct 7 2026

Gentle to moderate northerly breezes and moderate seas will prevail through Thursday. Strong to near gale force northerly winds will develop across the northern outer waters Friday, spreading across the rest of the waters Saturday into Sunday. Rough to very rough seas will build Friday into the weekend as a result. Long period southerly swell arrives Friday with long period westerly swell arriving Sunday.

FIRE WEATHER

Issued at 410 AM PDT Wed Oct 7 2026

Hot and dry conditions will lead to elevated fire weather conditions across the higher terrain through Thursday. Temperatures 10 to 20 degrees above normal and poor minimum relative humidity will continue away from the compressed marine layer at the coast. The higher terrain will experience active thermal belting, little-to-no recovery with nocturnal drying across the highest peaks, and thus prolonged burn periods. Winds remain the limiting factor, with diurnal winds prevailing except for light northerly/offshore flow overnight across the higher terrain. ERC values will rise to near records during the hot and dry conditions. A pattern change Friday into the weekend will bring cooler, moister, and windier conditions.

Sarment

MTR WATCHES/WARNINGS/ADVISORIES

CA...Dense Fog Advisory until 9 AM PDT this morning for CAZ006-505- 509-528>530.

Heat Advisory until 10 PM PDT Thursday for CAZ503-504-506-508- 510-512>518.

Coastal Flood Advisory until 1 PM PDT Thursday for CAZ506.

PZ...Dense Fog Advisory until 9 AM PDT this morning for Mry Bay.