textproduct: San Francisco Bay Area

KEY MESSAGES

Updated at 857 PM PDT Sat Oct 17 2026

- Hazardous beach conditions continue through Sunday night

- Cooling trend begins Sunday and persists into the work week

- Light rain showers possible mid-week

UPDATE

Issued at 857 PM PDT Sat Oct 17 2026

Saturday was the last hot day for the next week! Maximum temperatures today reached the low to mid-90s across the interior valleys, bay shorelines remained in the 80s, and the coast saw temperatures rise to the mid 70s to high 80s. A few hotspots even reached the high 90s to low 100s. Luckily, the offshore flow responsible for the warmth is weakening. The SFO-WMC pressure gradient increased by around 6 mb within the past 24 hours (was -10 mb Friday 8 PM and -4.4 mb Saturday 8 PM). In response, onshore flow continues to increase overnight ahead of the incoming dry, cold front. The presence of a moderate onshore push along with a deepening marine layer will support cooler weather beginning Sunday into the work week.

Navarrete

SHORT TERM

Issued at 139 PM PDT Sat Oct 17 2026 (This evening through Sunday night)

This afternoon is shaping up to be another very warm day with temperatures reaching into the upper 80s to low 90s across the interior, around the Santa Cruz region, and Monterey Bay region. Temperatures reached the low 90s around Monterey region as onshore flow was delayed. However, the onshore flow has returned cooling temperatures into the upper 70s to mid 80s. The immediate coastline is forecast to remain in the low-to-upper 70s. That said, the high pressure over northern California is weakening and will continue to do so through the remainder of the weekend.

The cooling trend will be more robust tonight and into Sunday as a dry frontal boundary moves across the Bay Area and north Central Coast. This will also allow for a slightly stronger onshore flow and deepening marine layer (albeit temporarily) and more seasonable temperatures. Thus, temperatures will be some 10-15 degrees or more cooler than today.

LONG TERM

Issued at 139 PM PDT Sat Oct 17 2026 (Monday through next Friday)

A more robust cool down will occur Monday as the upper-level trough deepens off of the West Coast, bringing temperatures to below seasonal averages. The trough becomes a cut-off low by Tuesday with its center approximately 350 miles west of San Francisco. This will bring a cold front through the region Monday night into Tuesday morning as the center of the low pressure system pushes inland across the south Central Coast and/or southern California Wednesday evening into Thursday. This will result in unsettled weather conditions across the region Tuesday through Thursday.

As far as precipitation and thunderstorm chances go, there is a 20- 40% chance of rain showers across the greater Bay Area and 30-60% chance across the Central Coast. The greatest potential for convection is now on Wednesday when the core of the low begins to move onshore. The greatest potential (generally 15% or less) will be over the offshore waters and Central Coast where the greatest instability will be located.

A further offshore and southern track of the low pressure system would result in less rainfall and lower probability for convection. However, if it were to move directly into the Central Coast (or even the Bay Area) we would have stronger winds, heavier rain, and increased potential for thunderstorms. Thus, be sure to check back on the forecast as the event draws nearer.

AVIATION

(06Z TAFS) Issued at 850 PM PDT Sat Oct 17 2026

Clear skies and VFR conditions prevail due to dry low levels. Expect VFR through most of tonight. Still looking like a 30% chc for MVFR at KSTS, but given the conf will keep the SCT to show some poss clouds. IFR to LIFR more likely at KHAF,KMRY,KSNS tomorrow with shallow moisture layer. Better chc for stratus by Monday AM. Overall conf remains high.

Vicinity of SFO...VFR. Gusty onshore this evening then weakening overnight. Onshore push again tomorrow afternoon with gusts over 20kts.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...VFR through early tonight. Need stratus to develop overnight and if it does it will be shallow leading to IFR to LIFR conditions Sunday AM. 15-20% for dense fog early Sunday for Monterey Bay region. VFR Sunday afternoon.

MARINE

(Today through Thursday) Issued at 1002 AM PDT Sat Oct 17 2026

Moderate to fresh northwesterly breezes will prevail through Monday with strong breezes across the northern outer waters. Widespread hazardous conditions will spread across the coastal waters as a result Sunday afternoon, likely continuing into Monday. Moderate seas will prevail across the inner waters with rough seas building across the outer waters Saturday through Monday, rebuilding again Tuesday. Light rain is expected Monday night through Wednesday.

BEACHES

Issued at 1002 AM PDT Sat Oct 17 2026

Hazardous beach conditions will be present at Pacific Coast beaches through Sunday and likely into next week. Long period southerly/southwesterly swell will bring an increased risk for sneaker waves and strong rip currents with breaking waves of 7 to 12 feet. Remain off jetties, piers, rocks, and other waterside infrastructure as waves can sweep across the shoreline without warning, pulling people into the sea. Remain out of the water to avoid hazardous surf with strong rip currents and never turn your back on the ocean!

Sarment

MTR WATCHES/WARNINGS/ADVISORIES

CA...Beach Hazards Statement through Sunday evening for CAZ006-505- 509-529-530.

PZ...Small Craft Advisory from 3 AM to 9 PM PDT Sunday for Pt Arena to Pt Reyes 0-10 nm.

Small Craft Advisory from 3 PM to 9 PM PDT Sunday for Pigeon Pt to Pt Pinos 0-10 nm-Pigeon Pt to Pt Pinos 10-60 NM-Pt Pinos to Pt Piedras Blancas 0-10 nm-Pt Reyes to Pigeon Pt 0-10 nm.

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