textproduct: San Francisco Bay Area

KEY MESSAGES

Updated at 927 PM PDT Thu Oct 8 2026

- Sharp cool-down this weekend and early next week

- Coastal flooding during high tides and large swell this weekend - Beach Hazards Saturday morning until Monday afternoon

- Light rain possible north Central Coast early next week

SHORT TERM

Issued at 1157 PM PDT Thu Oct 8 2026 (Tonight through Saturday)

Coastal stratus will be on the increase tonight and Friday morning. The onshore SFO-SAC pressure gradient has increased to 2.5 mb. Strong thermal ridging aloft, a compressed marine layer combining with daily solar input resulting in well above normal October temperatures has essentially reached its peak. Inland daytime high temperatures will still be warm Friday, but closer to 30 year (1991-2020) normal highs for October 9th.

Later Friday, Friday night and especially Saturday northwest winds will result in cold air advection. A major pattern shift will usher in strong upper level troughing i.e. much cooler air arriving here Saturday. The marine layer lower level temperature inversion will fully erode Saturday allowing plenty of vertical mixing. This pattern shift will bring a noticeable cool down, especially for inland areas.

LONG TERM

Issued at 1157 PM PDT Thu Oct 8 2026 (Saturday night through next Thursday)

Much cooler air from the surface to aloft continues to arrive Sunday. The strong cold core 500 mb low will sweep southward over our coastal waters with land overlap, resulting in gusty winds over the coastal waters and areas of gusty winds over land as well over the weekend. There's limited moisture availability with the low arriving from the north and a solid southerly push of drier air and lower precipitable water values on the back side of the low will mainly influence our forecast area over the weekend and early next week. The depth of cold air with the low of course will be passing over increasing sea surface temperatures as it moves south, which may produce showers over the southern forecast area early next week. 500 mb high pressure ridging will then move in from the west with dry weather and an uptrend back to near mid October normal temperatures.

AVIATION

(06Z TAFS) Issued at 1003 PM PDT Thu Oct 8 2026

VFR everywhere except for HAF, MRY, and SNS where LIFR-IFR conditions prevail through Friday morning. Fog development is possible overnight at these sites, including STS, though low to medium confidence on the exact timing. Overnight, winds remain light and gradually increase to a moderate onshore breeze Friday afternoon with locally stronger winds at SFO. The anticipated cold frontal passage is complicating the ceiling forecast tonight and Friday evening. The marine layer will deepen, but it will likely remain too shallow to reach the interior East and South Bay valley terminals. Moderate confidence for IFR ceilings at OAK and LIFR ceilings at the coastal sites plus STS.

Vicinity of SFO...VFR. Northwest winds gradually ease overnight. Low confidence on stratus impacts at SFO with scattered decks more likely. OAK continues to have a higher chance of borderline IFR-MVFR ceilings that will mix out by late Friday morning. Northwest winds increase that afternoon and remain elevated through the evening as the cold front passes through the region.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...IFR ceilings will gradually drop to LIFR overnight, resulting in foggy/misty conditions through Friday morning. Low to medium confidence on the exact timing of visibility reductions. VFR prevails Friday afternoon once onshore winds increase to around 10 kt. IFR ceilings are likely to return around sunset again on Friday.

MARINE

(Tonight through next Wednesday) Issued at 1003 PM PDT Thu Oct 8 2026

Hazardous marine conditions begin Friday through the weekend. North to northwesterly breezes increasingly become strong to near gale force as a cold front approaches the coast. Very rough wind driven seas build up to 15 feet with a low long period southerly swell arriving on Friday, which is then replaced by a moderate rough long period westerly swell on Sunday. Marine conditions gradually improve early next week as northwest winds ease.

FIRE WEATHER

Issued at 428 AM PDT Thu Oct 8 2026

Hot and dry conditions will lead to elevated fire weather conditions across the interior and higher terrain Thursday. Temperatures 10 to 20 degrees above normal and poor minimum relative humidity will continue away from the compressed marine layer at the coast Thursday. 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. Even though conditions become cooler and more humid Friday, windier conditions will keep elevated fire weather conditions across the interior and higher terrain through Friday.

Sarment

MTR WATCHES/WARNINGS/ADVISORIES

CA...Coastal Flood Advisory from 9 AM Friday to 3 PM PDT Tuesday for CAZ006-508-529-530.

Beach Hazards Statement from Saturday morning through Monday afternoon for CAZ006-505-509-529-530.

Coastal Flood Advisory until 4 PM PDT Wednesday for CAZ506.

PZ...Small Craft Advisory from 3 PM Friday to 3 AM PDT Saturday for Pt Arena to Pt Reyes 0-10 nm-SF Bay N of Bay Bridge.

Small Craft Advisory from 3 AM Friday to 3 AM PDT Saturday for Pt Arena to Pt Reyes 10-60 NM.

Small Craft Advisory from 9 PM Friday to 3 AM PDT Saturday for Pigeon Pt to Pt Pinos 10-60 NM.