textproduct: San Francisco Bay Area

KEY MESSAGES

Updated at 1102 PM PDT Sat Aug 15 2026

- Gradual warming and drying trend into next week

SHORT TERM

Issued at 1102 PM PDT Sat Aug 15 2026 (Tonight through Monday)

Heights will begin to rise Sunday as upper-level ridging nudges in from the east. We're already seeing an effect of this with a compressing marine layer bringing lower clouds and less inland extent. Sunday morning will offer another chance for drizzle along the coast and in the higher terrain. Temperatures will remain below normal under the marine layer influence with inland and higher elevation locations warming to near normal. Diurnal winds will keep smoke from the Timber Fire out to sea with downsloping (easterly) winds in the morning and onshore (northwesterly) winds in the afternoon.

LONG TERM

Issued at 1102 PM PDT Sat Aug 15 2026 (Monday night through next Saturday)

Global ensemble clusters are in agreement that upper-level ridging will nose, and ultimately build, into the Intermountain West through Thursday. Sensible weather wise, locations inland from and above the compressed marine layer (~1,000 feet) will moderate to near to slightly above normal. Along the coast, temperatures will remain below normal with evening/morning clouds. To put this event into context, 850 mb temperatures will increase to the 75th-90th percentile; even so, no records are forecast. Even with the warming and drying trend, heat and fire weather impacts are expected to remain minor. Fire weather wise, seasonably elevated conditions with rapid rates of spread on any wind-and-terrain aligned starts in receptive vegetation will be possible in higher terrain, specifically with the diurnal sea breeze in the afternoons/evenings.

AVIATION

(06Z TAFS) Issued at 1000 PM PDT Sat Aug 15 2026

Mostly IFR-LIFR stratus is expanding through the Petaluma Gap, into the SF Bay region, and across the southern Monterey Bay. Stratus is expected to continue developing through the night with clearing expected in the late morning hours on Sunday. Lingering onshore breezes will diminish to a light wind overnight. Moderate onshore winds will resume Sunday afternoon and evening, with a compressing marine layer resulting in lower ceilings and limited development inland, especially in the interior East Bay, as the marine layer clouds return Sunday night.

Vicinity of SFO... IFR stratus through the night will clear out late Sunday morning with moderate and potentially gusty west-northwest winds resuming in the afternoon. Low confidence in the timing of IFR- LIFR stratus return Sunday evening and overnight with high resolution model output showing the stratus deck developing right at the edge of the terminal.

SFO Bridge Approach... Similar to SFO.

Monterey Bay Terminals... MVFR-IFR stratus with light winds continues overnight. Stratus will mix out late Sunday morning and early afternoon (moderate confidence at MRY, high confidence at SNS), with breezy northwest winds expected in the afternoon and evening hours. Expect stratus to return rather early Sunday evening with IFR-LIFR ceilings expected.

MARINE

(Tonight through next Friday) Issued at 1000 PM PDT Sat Aug 15 2026

A gentle to moderate northwesterly breeze persists through Sunday with localized fresh gusts possible across the interior waters. A long period southerly swell of about 15 to 17 seconds will linger through Sunday. Winds increase to fresh to strong beginning Monday and remain elevated through the end of the forecast period. Seas of around 4 to 5 feet will build to 7 to 9 feet mid week.

MTR WATCHES/WARNINGS/ADVISORIES

CA...None. PZ...None.