Swell Matrix

Area Forecast Discussion

National Weather Service San Francisco CA

951 pm PDT Sun aug 30 2026

Short Term

, Issued at 1232 PM PDT Sun Aug 30 2026 (This evening through Monday night)

Stratus has retreated to the coast as of early afternoon with mostly sunny skies across the interior. Thus, temperatures inland temperatures will warm into the 70s to mid 80s and the lower 90s across the far interior. Meanwhile, persistent onshore flow and the marine layer will maintain cooler conditions near the coast, generally reaching into the 60s.

The marine layer is likely to deepen overnight to around 2000 feet and with an increased potential for coastal drizzle tonight and into midmorning on Monday. Expecting a slower clearing of stratus Monday morning as troughing off of the Pacific Northwest coast develops and deepens. As such, afternoon maximum temperatures will be 5 to 15 degrees below average. Heading into Monday night, another round of night/morning drizzle is expected along the coast and in the favored upslope regions.

Long Term

..issued at 1232 PM PDT Sun Aug 30 2026 (Tuesday through next Saturday)

Tuesday is now forecast to be the coolest day of the week with afternoon temperatures some 10 to 20 degrees below normal for this time of year. Temperatures remain below seasonal averages throughout much of next week with the potential for rain particularly across the North Bay late week as a weak frontal boundary sags southward across the region. This is as a cut-off low develops off of the northern California coast Tuesday with troughing persisting through the remainder of the week and potentially into next weekend. Still keeping an eye on the tropical eastern Pacific as it remains fairly active for any moisture that may be brought northward into California.

Aviation

(06z TAFS) Issued at 950 PM PDT Sun Aug 30 2026

VFR prevails except for nearly continuous stratus and fog/mist /MVFR-IFR/ along the immediate coast from Point Reyes southeastward. The earlier steady erosion on the northwestern edge of stratus has paused while nocturnal radiative cooling is underway; it is dry to very dry above the marine layer. Additional coastal stratus, fog/mist and drizzle will form including an inland intrusion tonight and Monday morning. Conditions improve to MVFR-VFR along the coastline Monday late morning and afternoon. Robust lower level cool air advection will deepen the marine layer especially Monday through Monday night. Stratus and patchy drizzle redevelop Monday night and early Tuesday.

Vicinity of SFO, VFR except stratus /MVFR/ ceiling 10z-18z Monday then a stratus ceiling redevelops 04z Monday evening. West wind 8 to 15 knots.

SFO Bridge Approach, Similar to SFO.

Monterey Bay Terminals, Stratus /MVFR-IFR/ tonight and Monday morning. Tempo light drizzle KMRY 10z-14z, conditions improve to MVFR-VFR late Monday morning. Stratus /MVFR/ returns Monday evening. West to northwest winds 5 to 15 knots.

Marine

(tonight through next Saturday) Issued at 934 PM PDT Sun Aug 30 2026

Fresh northwest winds diminish to a moderate breeze overnight, allowing rough seas to subside to moderate by Monday morning. The long period southerly swell continues to decrease tonight. Northwest to westerly winds remain gentle to moderate through the remainder of the work week as slight to moderate NW seas prevail.

Watches, Warnings, Advisories

Ca, None. PZ, Small Craft Advisory until 3 AM PDT Monday for Pt Arena to Pt Reyes 0-10 nm.

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

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