Swell Matrix

Area Forecast Discussion

National Weather Service San Francisco CA

515 pm PDT Sun may 10 2026

Short Term

, Issued at 1252 PM PDT Sun May 10 2026 (This evening through Monday)

Temperatures this afternoon are struggling to reach their forecasted highs. This is as a deeper marine layer around 1500 ft in the North Bay and 2000 ft in the Bay Area and Central Coast developed overnight. Again, where cloud cover lingers or is slow to dissipate across inland areas is where we are most likely to see cooler temperatures than previously forecasted. That said, inland clearing will still allow for temperatures to warm this afternoon as high pressure to the south of the region continues to strengthen.

Overnight, temperatures will cool into the upper 40s to mid 50s across most valley locations. Meanwhile, the higher ridges and peaks will likely bottom out in the upper 50s to 60s. If persistence holds, low clouds will fill back inland overnight, yet not expecting as much of an inland penetration as the marine layer is still on track to compress.

Monday is still on track to be the warmest day of the week, yet we are seeing less widespread Moderate HeatRisk across the interior. Mondays afternoon maximum temperatures are expected to be in the mid 80s to lower 90s across the interior with cooler conditions near the coast as a shallow marine layer and onshore flow will persist. However, these temperatures could be off by a few to several degrees where cloud cover develops and lingers. Tricky forecast as high pressure aloft supports warming afternoon temperatures, yet the marine influences have been winning out.

Long Term

..issued at 1252 PM PDT Sun May 10 2026 (Monday night through next Saturday)

The pattern begins to shift Monday night into Tuesday as a trough of low pressure approaches the Pacific Northwest and northern California. Thus, temperatures will cool by several degrees on Tuesday, yet are likely to remain above seasonal averages. A cut-off low pressure system is forecast to develop and move inland Tuesday night and into Wednesday bringing even cooler and unsettled weather to the region. We are still expecting drizzle and/or light rain Tuesday night through Thursday morning as a result of the mid/upper level cut-off low moving inland across northern California or the Bay Area. Rainfall amounts generally will remain less than a few hundredths of an inch or so.

More of a zonal flow returns by late week and will persist through the upcoming weekend. This will result in a warming and drying trend through this timeframe.

Aviation

(00z TAFS) Issued at 515 PM PDT Sun May 10 2026

If you guessed satellite analysis for what this meteorologist started with for the aviation forecast, you'd be correct. It has been quite a fascinating journey the past few days watching the status of the stratus, which is what we're doing yet again. This evening's observations include Mainly VFR conditions with the exception being along the San Francisco Peninsula and Monterey coastlines where sites are reporting MVFR cigs. These will likely hold and even build for the overnight hours bringing MVFR to IFR ceilings. The marine layer is expected to be around 1000ft tonight which means the onset of stratus in the valleys will be delayed or non-existent. Most sites have hints of cigs, with them lifting by mid to late morning. VFR conditions are expected for the majority of the region by Monday afternoon. Medium to high confidence in the forecast.

Vicinity of SFO, Breezy westerly winds are coming online and should hold for a couple of hours, before falling to 10kt or less after 6Z. The challenge outside of winds is the stratus. Satellite imagery and webcams show lingering stratus near the San Bruno Gap, but it has been gradually eroding this afternoon. With the marine layer expected to be around 1000ft again, we should see the return of stratus tonight. Kept the pessimism in the TAFs with IFR cigs based on the last few nights, but time will tell if go that low or stay in the MVFR category. Stratus looks to dissipate mid to late morning, with breezy westerlies returning Monday afternoon. Will need to keep an eye on the marine layer again tomorrow night. Medium confidence in the forecast.

SFO Bridge Approach, Similar to SFO.

Monterey Bay Terminals, A small band of stratus remains around the Monterey Peninsula, which has been flirting with KMRY the last few hours. Expect this to build back in this evening bringing MVFR to IFR cigs to the terminals. Stratus should begin to erode by mid to late morning, though a few clouds could linger around KMRY.

Marine

(tonight through next Saturday) Issued at 515 PM PDT Sun May 10 2026

Moderate seas and a fresh to strong northwest breeze with isolated near gale force gusts continuing through tonight. Locally gusty conditions are likely across the San Pablo and San Francisco Bays where terrain promotes wind funneling. Winds ease late tonight across the inner waters then across the outer waters tomorrow becoming a moderate northwest breeze. Winds increase and seas build again mid to late week.

Watches, Warnings, Advisories

Ca, None. PZ, Small Craft Advisory until 9 PM PDT this evening for Mry Bay- Pigeon Pt to Pt Pinos 0-10 nm-Pt Pinos to Pt Piedras Blancas 0-10 nm-Pt Reyes to Pigeon Pt 0-10 nm.

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

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

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

Visit this site often? Consider supporting us with a $10 contribution.
Learn more