, Issued at 1214 PM PDT Wed Apr 1 2026 (This evening through Thursday)
A gale force low pressure system off the coast of the Washington/Canada border and its attendant cold front will be our weather maker the next 24 hours. Ahead of the cold front, southwesterly winds will increase with gusts of 20-30 mph and up to 40 mph in the higher terrain. Isolated pre-frontal rain showers are possible with the best chances for rain holding off until later this afternoon, slowly spreading from north to south with the cold front. So as far as a wet commute home goes, that will likely remain confined to the North Bay with the slow progression of the cold front. That means most of the rainfall south of the Golden Gate Bridge will fall overnight. Rainfall totals on the order of 0.10"- 0.25" are expected with locally higher totals in the higher terrain of the North Bay with the help of orographic lift and locally lower totals in the Interior Central Coast. Even with the over performance of yesterday's rainfall, no adverse impacts are expected with the exception of slick roadways. It is possible that today's rainfall over performs as well due to the recency bias of the well above normal temperatures and dry spell that has occurred over the last four weeks. This is actually a best case scenario for both water storage and fire weather concerns. Similar to yesterday, the best chances for thunderstorms will remain off to our north and east with our region being instability limited.
..issued at 1214 PM PDT Wed Apr 1 2026 (Thursday night through next Tuesday)
The warming and drying trend will commence right behind the cold front as surface high pressure noses in from the Eastern Pacific Ocean. This will veer winds to become northwesterly with the tightened surface pressure gradient yielding strong winds in exposed areas like the higher terrain and over the waters. Very dry air will get funneled in behind the cold front with PWAT values forecast to be between the daily minimum (0.18 inches) and tenth percentile (0.34 inches) for 12Z tomorrow. ECMWF and GFS ensembles are in agreement that the SFO-WMC pressure gradient will change from positive (onshore) to negative (offshore) tomorrow night, but that's about where the agreement ends. The uncertainty lies in how the aforementioned high builds into the Intermountain West and how strong it gets. The ECMWF deterministic and ensemble continues to offer a stronger solution than its GFS counterparts. Both models and their means show a relative minimum occurring at 5 AM Friday with the ECMWF ensemble mean at -9.26 mb and the GEFS ensemble mean at -8.03 mb. 24 hours later at 5 AM Saturday, the ECMWF ensemble mean bottoms out at -9.91 mb while the GEFS ensemble mean is well on its way to relaxing at -5.50 mb. Nonetheless, confidence is high that a moderate offshore flow event will transpire Thursday night with the gradient beginning to weaken by Sunday morning and returning to positive by Monday. This will equate to gusts of 40 to 50 mph in the North Bay Interior Mountains with gusts of 30 to 40 mph in the East Bay Hills, Eastern Santa Clara Hills, and Santa Cruz Mountains. Well above normal temperatures are expected over the weekend with Saturday being the warmest day of the week. Chances for rain may return as early as Tuesday with the help of an upper-level trough.
(00z TAFS) Issued at 444 PM PDT Wed Apr 1 2026
Breezy west-southwest winds will persist out ahead of a cold front that arrives around 04z across the North Bay and will be through the Monterey Bay terminals around 10Z. The mix of of MVFR/VFR cigs will continue until after the front is through. The airmass behind the front is very dry with quick clearing expected to VFR, however gusty west- northwest winds will persist through much of the remaining TAF period in the post-frontal environment.
Vicinity of SFO, Similar to SFO.
SFO Bridge Approach, Scattered light rain through late tonight out ahead and along a front that arrives in the Bay Area around 07Z. Expect a mix of MVFR/VFR cigs until the front is through and quickly becomes VFR with gusty west-northwest winds around 09Z.
Monterey Bay Terminals, VFR conditions are expected until a cold front arrives around 09Z with a drop into MVFR cigs until around 12Z with scattered light rain. VFR for the remainder of the day once the front moves through with breezy west-northwest winds.
(tonight through next Monday) Issued at 444 PM PDT Wed Apr 1 2026
Southwesterly breezes will increase ahead of the cold front this afternoon and veer to become fresh and northwesterly tonight. The cold front will bring light rain this afternoon into tonight. Widespread hazardous conditions arrive tomorrow and continue into Friday with strong northerly breezes and rough seas. Northerly breezes diminish and seas abate by this weekend.
Ca, None. PZ, Small Craft Advisory until 3 AM PDT Friday for Pt Arena to Pt Reyes 0-10 nm-Pt Arena to Pt Reyes 10-60 NM-Pt Reyes to Pigeon Pt 0-10 nm-SF Bay N of Bay Bridge.
Small Craft Advisory from 3 AM Thursday to 3 AM PDT Friday for Mry Bay-Pigeon Pt to Pt Pinos 0-10 nm-Pigeon Pt to Pt Pinos 10-60 NM-Pt Pinos to Pt Piedras Blancas 0-10 nm.
