, Issued at 1258 AM PDT Sat Sep 5 2026 (Today and tonight)
On Thursday the presence of mid to upper level troughing and a surface cool front brought many (but not all locations) an early rain, in some cases an early September daily record breaking rain. Atypical cool air aloft for early September carried over to Friday and plenty of cool air aloft is still lingering at this hour early Saturday morning. With current temperatures broadly in the 50s/60s, coolest at higher elevations, it's relief e.g. for a time of year here when it can easily be much warmer at higher elevations in the lower level temperature inversion under high pressure aloft. Mountain top air temperatures from Mt St Helena all the way to Chews Ridge are currently in the lower 50s. Mt Hamilton 30 year early Sep normal low for example is 62F.
Recently sea surface temperatures in our coastal waters have bumped upwards to the lower to mid 60s north to south, now 2F to 5F above Sep normals. This is resulting in a warming effect on nearby coastal locations where daily minimums are remaining a few to several degrees warmer than normal. The usual night/morning chill may be noticeably absent in the last few days.
If you're enjoying the daytime temperatures from the coast to far inland, daytime highs today will be similar to maybe a few degrees warmer with 60s/70s coastside/bayside to the upper 70s to lower 80s inland.
..issued at 1258 AM PDT Sat Sep 5 2026 (Sunday through next Friday)
Forecast daytime highs Sunday will be similar to Saturday's highs, 60s/70s coastside/bayside to the upper 70s to lower 80s inland. Dry weather will continue Sunday. A weakening or break in mid to upper level troughing will begin on Labor Day with thermal ridging developing aloft resulting in a warming trend across the forecast area. This will result in daytime highs warming back to and slightly above normal e.g. 80s to lower 90s inland to far inland locations.
Global models are still showing redevelopment of 500 mb troughing over the eastern Pacific during the middle of next week. 00z guidance however is showing some retrogression of the upper level trough. This will be at the same time remnant tropical moisture moves northward and may get entrained into the trough. Our official forecast shows light rain next week, and it still bears monitoring however the precipitation forecast over our area has trended drier.
(12z TAFS) Issued at 426 AM PDT Sat Sep 5 2026
Patchy stratus is developing along the SF Bay shoreline while fog is developing across the North Bay Valleys. Not anticipating stratus/fog to spread beyond the already impacted airports (STS, APC, HAF, potentially OAK and SFO). Stratus/fog should dissipate by late morning (approx. 17/18Z) with VFR persisting through the remainder of the day. Expecting gustier onshore winds to prevail again today with the SFO-WMC gradient peaking around +9 mb this afternoon/evening. Occasional gusts to between 20 to 25 knots are possible at SFO and SJC this afternoon/evening before winds ease tonight. The marine layer struggles to redevelop again tonight which will keep stratus patchier again tonight and see a late stratus return. Stratus redevelopment becomes more likely closer to 12Z tomorrow (end of TAF period) but more likely will fall after 12Z (into the next TAF period).
Vicinity of SFO, Patchy stratus is filling in over the SF Bay and reaching towards SFO. Guidance indicates some potential for patchy stratus to fill in over SFO this morning but confidence is mixed as to if clouds will stay scattered or if a ceiling will develop. If a ceiling develops it will likely be between 12Z to 16Z. Gusty onshore winds return this afternoon/evening with gusts to around 25 knots possible. Winds decrease overnight with some potential for stratus to reach SFO after 12Z tomorrow morning.
SFO Bridge Approach, Generally similar to SFO. Satellite shows stratus developing over the SF Bay within the SFO Bridge Approach region. CIGs are likely on the IFR-MVFR border with SFO reporting scattered clouds at 1100 feet. Stratus will clear by late this morning with some potential for stratus to redevelop early tomorrow morning.
Monterey Bay Terminals, VFR expected through late tonight. Breezy onshore winds develop during the afternoon/evening before winds ease overnight. Low to moderate confidence that stratus will redevelop early tomorrow morning given the fact that the marine layer is struggling to redevelop this weekend. Stratus becomes more likely closer to 12Z/into the end of the next TAF period.
(today through Thursday) Issued at 426 AM PDT Sat Sep 5 2026
West to northwest breezes will be gentle to moderate through the beginning of next week. Diurnal moderate to strong breezes are expected across the San Pablo, San Francisco and Monterey Bays today into the beginning of next week. Long period southerly swell will continue to impact the coastal waters through much of the upcoming week. Fresh to strong gusts become more widespread late weekend into early next week before winds decrease by midweek.
Issued at 1010 PM PDT Wed Sep 2 2026
A Beach Hazards Statement is in effect Friday-Monday as the swell from both Hurricane Marie and Hurricane Karina reaches the coast. As these hurricane whip up the ocean, the waves travel over 1,000 miles in all directions, gradually flattening out to low amplitude, but long period swell. These waves aren't very intimidating if you're on a boat in the open ocean, but the long period allows them to push much farther up the beach. Long period swell always increases the chance for sneaker waves, but that's particularly true this weekend since there are 2 different sets of southerly swell, and their energy will periodically combine. In addition to sneaker waves, expect strong rip currents and breaking waves up to 10 ft. As this is a holiday weekend and the weather is otherwise pretty nice, the exposure to the risk is high. Avoid the water if you're not an expert swimmer. If caught in a rip current, swim parallel to shore until you stop feeling the pull. Even on the beach, be prepared for sneaker waves this weekend and never turn your back on the ocean.
Ca, Beach Hazards Statement through Monday evening for CAZ006-505- 509-529-530.
PZ, Small Craft Advisory from 9 AM to 9 PM PDT Sunday for Mry Bay.
Small Craft Advisory from 9 AM Sunday to 3 AM PDT Monday for Pigeon Pt to Pt Pinos 0-10 nm-Pt Pinos to Pt Piedras Blancas 0-10 nm.
