, Issued at 1204 PM PDT Sat Sep 26 2026 (This evening through Sunday night)
The stratus deck has mixed out to the immediate coast of Marin County and the Ocean Beach side of San Francisco and lurking near or just off the coast of San Mateo County. High clouds continue to flow over the North Bay and will continue to do so through the day, as the stratus deck returns to many of the coastal valleys this evening into the overnight period.
A developing trough with an axis around 600 miles west of Cape Mendocino is approaching the West Coast, digging deeper into the upper level flow as it does so and eventually dropping deep enough to cross into the California coast, where it should further develop into a cut-off low somewhere around the North Coast and the northern half of the Central Valley through the latter portion of Sunday. The influence of the cut-off low will bring cooler and more moist conditions to the region. High temperatures will range around 5 to 15 degrees below seasonal averages for today and Sunday, with highs in the inland valleys reaching the middle 70s to lower 80s today and the 70s on Sunday. High temperatures in the warmest portions of southern Monterey County will range from the middle 80s to lower 90s today, and the upper 70s to middle 80s on Sunday. Meanwhile, the Bayshore regions should expect highs in the upper 60s to upper 70s on Saturday and the middle 60s to middle 70s on Sunday, while the Pacific coast remains relatively cool with highs in the upper 50s to middle 60s on both days.
As the cut-off low moves across the state through the weekend, cooler temperatures and some incoming moisture should result in a wetter mid-layer, around the 300-500 mb layer. Exceedingly dry lower layers should cause the evaporation of most precipitation that may result, but can't rule out a few sprinkles overnight for the coastal regions and the highest peaks.
..issued at 1204 PM PDT Sat Sep 26 2026 (Monday through next Friday)
Ridging should return to the region on Monday as the low moves into the Mojave Desert, setting up pushes of higher elevation offshore flow each morning from Monday to Wednesday, chiefly across the North and East Bay interior mountains. The strongest push looks to be on Tuesday morning with wind gusts of 25 to 35 mph possible in the interior mountains of the North Bay. The potential for wind gusts above 35 mph is greatest at the ridgeline of the Vaca Mountains along the eastern border of Napa County.
Otherwise, the arrival of the ridge should allow for temperatures to warm for the next week. By Tuesday, highs should reach the middle 80s to middle 90s in the inland valleys, the middle 70s to the middle 80s for the Bayshore regions, and the 60s to the lower 70s for the Pacific coast. These highs should basically remain stable through the rest of the 7-day outlook as ensemble model means and cluster guidance suggest that the ridging pattern should stick around in some shape or form into the upcoming weekend and possibly beyond.
(06z TAFS) Issued at 848 PM PDT Sat Sep 26 2026
A mix of VFR and MVFR as the marine layer begins to gradually strengthen out ahead of an advancing upper trough. Moderate confidence that a majority of the terminals see MVFR/IFR ceilings, with plenty of uncertainty in the extent and exact timing for the North Bay and Bay Area sites.
Vicinity of SFO, The KOAK sounding showed a weak marine layer around 1000ft, but should continue to gradually strengthen and organize. There is dry air aloft mixing to the surface which provides uncertainty on the extent and exact timing. Went on the more pessimistic side of most guidance, bringing MVFR ceilings in the in the pre-dawn hours, but may not happen until after sunrise Sunday. Expect some coastal drizzle where stratus develops. Once the stratus lifts by late morning Sunday, VFR for a majority of the forecast period thereafter.
SFO Bridge Approach, Similar to SFO.
Monterey Bay Terminals, Stratus ceilings will hover around MVFR/IFR until mid/late Sunday morning with possible drizzle, with VFR for the remainder of the afternoon and early evening. MVFR ceilings expected to return around sunset Sunday evening.
(tonight through next Friday) Issued at 848 PM PDT Sat Sep 26 2026
Moderate north winds will persist through the weekend, becoming strong and gusty as high pressure builds over the the EPAC which will result in a tightening pressure gradient over the coastal waters, with the strongest gusts occuring along the outer coastal waters from Monterey Bay south to Big Sur. Tropical activity will produce long period southerly swell by the middle of the week.
Ca, None. PZ, Small Craft Advisory from 9 AM Sunday to 3 AM PDT Monday for Mry Bay-Pigeon Pt to Pt Pinos 0-10 nm.
Small Craft Advisory until 9 PM PDT Monday for Pt Pinos to Pt Piedras Blancas 0-10 nm.
Small Craft Advisory until 9 AM PDT Monday for Pt Arena to Pt Reyes 10-60 NM.
Small Craft Advisory until 9 PM PDT this evening for Pigeon Pt to Pt Pinos 10-60 NM.
