, Issued at 1209 PM PDT Tue Aug 11 2026 (This evening through Thursday morning)
Stratus clouds linger along the immediate coast through the day, before coming into the inland valleys overnight into Wednesday morning. Smoke from the Timber Fire south of Big Sur continues to be transported northwards into the Monterey Bay region due to southwesterly transport winds, and this is expected to continue through the next couple of days. For air quality forecasts, refer to products issued by the Monterey Bay Air Resources District within the Central Coast, and the Bay Area Air Quality Management District within the San Francisco Bay Area.
The weather pattern is dominated by a developing upper level trough that will continue a cooling and moistening trend through the next couple of days. Today's high temperatures range from the 80s and lower 90s in the inland valleys, up to the middle 90s in the warmest interior spots, the 70s and lower 80s along the Bays, and the lower to middle 60s along the Pacific Coast. Lows tonight into Wednesday morning range from the 50s and lower 60s within the lower elevations, up to the middle 60s to lower 70s above the marine layer influence at around 2000 feet. Overnight drizzle is possible along the coast and within favored upslope foothill areas through the Petaluma Gap and within the East Bay.
For Wednesday, attention turns to an upper level low that is currently meandering around 300 miles southwest of Point Conception, where space- and ground-based observations have pointed to some lightning occuring within a high-based thunderstorm cell. Through the next couple of days, that cell will start to move along a moisture gradient, which could locally enhance the lapse rates, into the Central Coast, with around a 10-15% probability of high-based showers and thunderstorm activity across Monterey and San Benito Counties between Wednesday afternoon and the early part of Thursday morning. Primary threats are gusty outflow winds and the potential for dry lightning and its attendant fire weather implications; see the FIRE WEATHER section for more details. Main question right now is if the cell will hold together as it approaches the coast. Water vapor imagery is showing a layer of drier air within the cell's path, which could disrupt the system as it approaches California. Elsewhere, the general cooling trend continues as highs reach the upper 70s to middle 80s inland, the upper 60s to the middle 70s near the Bays and the lower to middle 60s along the Pacific coast.
As a final note, minor coastal flooding is possible across the low lying bayshore areas of the San Francisco, San Pablo, and Monterey Bays at the highest high tide through Wednesday night/Thursday morning. At the San Francisco tidal gauge, high tide is expected to be 1.6 ft above normal (7.44 ft MLLW) at 10:57 PM Tuesday 8/11 and 1.4 ft above normal (7.24 ft MLLW) at 11:49 PM Wednesday 8/12. High tides may result in flooding along coastal trails, cut off access to some low-lying coastal areas and beaches, and bring water and waves farther up the beach than typical. If travel is required, allow extra time as some roads may be closed. Do not drive, bike, or walk around barricades or through water of unknown depth.
..issued at 1209 PM PDT Tue Aug 11 2026 (Thursday afternoon through next Monday)
The cooling trend continues through Thursday with highs in the inland valleys dropping into the 70s, or around 10 to 20 degrees below the seasonal averages, possibly as high as the middle 80s in the warmest spots, and highs into the 60s close to the Bays. Beginning on Friday, the trough begins to flatten out, allowing for gradual warming to occur, although temperatures will remain below seasonal averages given that the troughing pattern never really goes away, it just merges with another trough coming in from the eastern Pacific and lurks just offshore for the weekend before migrating back over the West Coast for the early part of next week, when highs will be in the middle 70s to lower 80s inland and the middle 60s to lower 70s near the Bays.
(18z TAFS) Issued at 1133 AM PDT Tue Aug 11 2026
Stratus has retreated to the coastline where it'll remain for the rest of the day. Widespread VFR throughout the day with moderate onshore breezes increasing in the afternoon before easing around sunset. The marine layer pushes onshore again, impacting coastal sites first before sunset. The stratus will then continue its push to inland sites overnight, around/after midnight. Medium confidence on how expansive the stratus layer will be tonight considering the transition period we are in with the passing upper level trough. The trough has the potential to deepen the marine layer up to 1800-2000 feet. As a result, low confidence on whether SJC will develop an MVFR ceiling early Wednesday morning as it is dependent on marine layer depth. Overall, expect a mixture of low-end MVFR to IFR ceilings with a similar clearing time as today (17-18Z Wednesday).
Vicinity of SFO, VFR into the evening with moderate northwest winds increasing this afternoon to 15-18 kt. Higher confidence for OAK to develop an MVFR ceiling around midnight this TAF period. Low to medium confidence for SFO to develop a ceiling given the recent trend, but hinted at the potential for MVFR ceilings to develop shortly after OAK. Any cloud ceiling that develops south of the Bay Bridge is expected to clear late Wednesday morning.
SFO Bridge Approach, Similar to SFO.
Monterey Bay Terminals, VFR through the afternoon with smoke/haze in the local airspace due to a nearby fire on the Big Sur coastline. Onshore winds increase through the afternoon and decrease through the evening/overnight. Low-end MVFR to IFR ceilings are expected to impact both terminals early this evening before sunset. Coastal drizzle is possible in the overnight hours, but currently have low confidence on exactly when and how long it will last.
(today through Sunday) Issued at 404 AM PDT Tue Aug 11 2026
Fresh to strong northwest winds will continue to produce rough seas across the northern outer waters through Thursday. Long period southerly swell will gradually increase from 15 seconds through the middle of the week, up to 17 to 19 seconds by Friday into Saturday.
Ca, Coastal Flood Advisory until 2 AM PDT Thursday for CAZ006-506- 508-529-530.
PZ, Small Craft Advisory until 9 AM PDT Thursday for Pt Arena to Pt Reyes 10-60 NM.
