textproduct: San Francisco Bay Area

KEY MESSAGES

Updated at 1240 PM PDT Sat Aug 29 2026

- Cooling trend continues through at least midweek

SHORT TERM

Issued at 1240 PM PDT Sat Aug 29 2026 (This evening through Sunday night)

Mostly sunny sky conditions have return to the region this afternoon. This will lead to warmer conditions today over the North Bay with the lack of mid/upper level high clouds. However, temperatures across the region with be a few to several degrees below normal as an mid/upper level low pressure system moves into the Pacific Northwest and British Columbia.

The marine layer is forecast to deepen through the weekend. However, with clearing skies off of the North Bay coast this afternoon, less confidence for a return of stratus/fog overnight and into Sunday morning. Still anticipate at least a patchwork of stratus/fog to develop late this evening and moreso into Sunday morning along the coast and into the adjacent valleys. For Sunday, expecting more of the same as troughing persist along the West Coast.

LONG TERM

Issued at 1240 PM PDT Sat Aug 29 2026 (Monday through next Friday)

A reinforcing trough develops and begins to deepen off of the Pacific Northwest coast through the middle of the upcoming week. As a result, afternoon temperatures will be some 5 to 15 degrees below normal for this time of year. This will system will likely bring rainfall to the Pacific Northwest. By late week, the NBM is suggesting a better chance of rain/rain showers as the trough off of the West Coast continues to deepen and potential drags a weak frontal boundary across the region. There is still low to moderate confidence of this occuring.

AVIATION

(00Z TAFS) Issued at 541 PM PDT Sat Aug 29 2026

VFR prevails across the forecast area except for wildfire smoke reducing slant range and surface visibilities in southern Monterey County. A well established deep layered mid-latitude wind flow returned last night and today which thoroughly dried out the atmosphere at and above the lower level subsidence inversion (temperature inversion based at 1600 feet per latest 00z Oakland upper air sounding). This drying combined with surface heating and fully mixed out even lingering coastal stratus and fog. Independent of the 500 mb pattern, thermal ridging remains between 925 mb and 700 mb tonight and Sunday. Model forecasts show stratus and fog returning tonight and Sunday morning, though it'll take time for redevelopment. A dry atmosphere above the lower level temperature inversion will result in radiative cooling tonight to daybreak Sunday. This and any near surface cool air advection will help coastal stratus and fog redevelopment tonight and early Sunday morning. Most inland locations likely stay VFR tonight and Sunday.

Vicinity of SFO...VFR except tempo stratus /IFR/ 11z-15z Sunday. West wind 16 to 25 knots until 05z this evening, then west wind 10 knots tonight and Sunday morning. West wind 15 to 22 knots Sunday afternoon to mid evening.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...VFR. It'll take a while for post sunset radiative cooling combining with gentle upslope cooling to result in stratus and fog/mist /IFR-LIFR/ redevelopment. Tempo stratus and fog/mist /LIFR/ forecast 09z-14z, prevailing LIFR until late Sunday morning. Stratus, fog/mist mix out to VFR 17z Sunday. Winds mainly west to northwest 5 to 15 knots.

MARINE

(Tonight through next Thursday) Issued at 458 PM PDT Sat Aug 29 2026

Fresh northwest breezes with strong to near gale force gusts steadily diminish to gentle by Monday. A long period southerly swell around 17 to 18 seconds persists into Sunday. Wind driven seas briefly build to rough this afternoon and gradually subside back to moderate by the beginning of the work week.

MTR WATCHES/WARNINGS/ADVISORIES

CA...None. PZ...Small Craft Advisory until 3 AM PDT Sunday for Mry Bay-Pigeon Pt to Pt Pinos 0-10 nm.

Small Craft Advisory until 3 AM PDT Monday for Pt Arena to Pt Reyes 0-10 nm-Pt Arena to Pt Reyes 10-60 NM.

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