textproduct: San Francisco Bay Area

SYNOPSIS

Issued at 247 AM PDT Wed Jun 11 2025

Daily pattern of the return of marine layer clouds overnight through the morning hours, some coastal drizzle, and breezy afternoon onshore winds continues. Temperatures remain in the upper 50s and into the 60s at the coast, the 70 to 80s for areas more inland, and into the 90s for the far interior.

SHORT TERM

(Today and tonight) Issued at 247 AM PDT Wed Jun 11 2025

The marine stratus push isn't as widespread as previous nights, but the coast and favored valleys are still seeing plenty of cloud cover. The expansion of the marine layer allowed for clouds to be slightly less lower than previous days, and less pockets of fog. Short term models are hinting earlier clearing than the last few days for the North Bay Valleys and the Salinas Valley and less coastal drizzle chances to start the day.

Some fine-tuning was done on todays temperatures, which are trending overall cooler than yesterday, but only by a few degrees in the interior areas, and just barely along the coast. Today is setting up to be one of the cooler days of the forecast, with a slight short wave trough enhancing the onshore flow.

Cloud cover will be slower to build inland this evening, with less overall coverage than this morning, but the coastal cloud cover will still be strong.

LONG TERM

(Thursday through Tuesday) Issued at 247 AM PDT Wed Jun 11 2025

The reduced cloud cover will allow for earlier clearing for all but the immediate coast on Thursday morning. This will also lead to warmer temperatures for the the areas that are slightly inland, but not some much for the interior areas that haven't been seeing cloud cover for the last few days.

The persistent zonal pattern aloft will keep the onshore flow going through much of the forecast, with temperatures mostly being affected by how much and how persistent cloud cover is each day. A little less cloud cover for Friday, then a little more for Saturday. But the variations in day to day temperatures still don't look to be terribly drastic. The difference between the immediate coast and inland areas, however, will still be interesting to say the least with some potions of the coast sticking to the upper 50s and the interior areas peaking in the 90s.

The flow does change slightly in the late weekend and into the next work week as a trough enters the area. The reduction in pressure from the trough will cause the marine layer to deepen, and lead to more moisture movement inland. It will also allow some cooling for the more interior areas, but only slight cooling.

The big question is the speed at which the trough exits and what happens after. Long-term model agreement seems to be falling apart into the next work week as some models point to the trough exiting Monday and going back to zonal flow, while others keep the trough around for a few days. Some even snap quickly to a ridge pattern, calling for another warming and drying trend in the mid week. This will be something to keep an eye on as models continue to try to figure this on out, be sure to keep checking back in!

AVIATION

(06Z TAFS) Issued at 1001 PM PDT Tue Jun 10 2025

Stratus beginning to build inland this evening, expected to continue through the night and continuing through Wednesday morning, with inland clearing through the afternoon. Have opted to continue with a generally persistent forecast for the terminals as the daily patterns have remained rather consistent. If the marine layer does compress at any point, less stratus intrusion inland and earlier clearing times Wednesday morning would be the result. MVFR-IFR conditions are generally expected through the night with some LIFR ceilings possible at the immediate coast. Inland terminals will be the first to clear Wednesday morning, followed by the North Bay. Wednesday evening, lower confidence in stratus at the North Bay terminals as high resolution models hold off on stratus formation.

Vicinity of SFO... MVFR-IFR stratus through the overnight period. Westerly winds remain breezy and gusty through the evening hours, with gusts abating overnight before picking up again Wednesday afternoon. Moderate confidence in a period of scattering at the terminal sometime between 18-00Z Wednesday, with stratus returning sometime afterward. Confidence is low in the exact timing of stratus, and the SCT group starting at 03Z Wednesday evening accounts for the possibility for the terminal to sit on the edge of the stratus flow through the Golden Gate. In any case, high confidence for a stratus ceiling at the terminal by 09Z Thursday.

SFO Bridge Approach... Approach path remains clear for a couple more hours, although stratus over the terminal is likely precluding visual approaches. For Wednesday morning, higher confidence that the approach path clears before the terminal does, with westerly flow potentially keeping a stratus feed right at the edge of SFO.

Monterey Bay Terminals... IFR stratus at the terminals dropping to LIFR sometime overnight. Highest confidence for clearing stratus Wednesday morning along the northern side of the Monterey Bay. Moderate confidence for clearing at SNS with lower confidence for the exact timing, as high resolution models suggest an earlier clearing time than a persistence forecast. Lower confidence for the clearing of stratus at MRY, with the most likely outcome being a temporary scattering sometime between 20-02Z. Low to moderate confidence of SNS getting a ceiling before the end of the TAF period, with high resolution modeling suggesting a stratus deck remaining just to the north of the terminal for a few hours before building southward.

MARINE

(Today through Monday) Issued at 247 AM PDT Wed Jun 11 2025

Fresh to strong northwesterly breezes will prevail through the week with gale force gusts developing in the afternoons along the coastal jet regions of Point Reyes and Point Sur. Moderate to rough seas will prevail through the week.

MTR WATCHES/WARNINGS/ADVISORIES

CA...None. PZ...Small Craft Advisory until 3 AM PDT Thursday for SF Bay N of Bay Bridge.

Small Craft Advisory from 9 AM this morning to 9 PM PDT this evening for Mry Bay.

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

Small Craft Advisory from 3 PM this afternoon to 3 AM PDT Friday for Pt Reyes to Pigeon Pt 0-10 nm.

Small Craft Advisory from 9 AM this morning to 3 AM PDT Friday for Pigeon Pt to Pt Pinos 0-10 nm-Pigeon Pt to Pt Pinos 10- 60 NM.

Small Craft Advisory until 3 AM PDT Friday for Pt Arena to Pt Reyes 10-60 NM-Pt Pinos to Pt Piedras Blancas 0-10 nm.