Issued at 712 PM PDT Wed Sep 3 2025
Stratus is just starting to expand inland as the Sun sets across the Bay Area and Central Coast. Smoke from the Salt/14-2 Fire in the western tip of Fresno County just across the Monterey County line may impact southeastern Monterey and southern and eastern San Benito counties through the next few days, dependent on local wind conditions. The Monterey Bay Air Resources District is responsible for air quality forecasts in the region. Otherwise, the forecast generally remains on track.
DialH
, Issued at 1228 PM PDT Wed Sep 3 2025 (This evening through Thursday)
Zonal flow continues through the remainder of Wednesday before giving way to a weak upper level trough early Thursday morning. Temperatures will continue their subtle downwards trend Wednesday to Thursday with highs dropping another 2-4 degrees across the region. High temperatures on Thursday will generally be in the mid 70s to 80s across the interior and 60s to low 70s along the coastline. The exception will be for our typical hotspots (far interior North Bay, Byron, and interior Central Coast) where highs will continue to be in the upper 80s to mid 90s. Winds will stay diurnally breezy across the region with gusts to around 25 to 30 mph across the Salinas Valley and Altamont Pass region.
The marine layer is expected to remain between 1000-1500 ft tonight into early Thursday morning. This is expected to bring drizzle and patchy fog along the coastline. The marine layer is set to deepen to around 1800-2000 ft by Thursday night as zonal flow gives way to weak upper level troughing. This will result in morning coastal drizzle being a daily occurrence into this weekend.
..issued at 1228 PM PDT Wed Sep 3 2025 (Thursday night through next Tuesday)
Upper level troughing will deepen over the West Coast Friday into next week. Temperatures continue to cool Friday into the 70s to mid 80s across the interior. Temperatures will cool another 1-3 degrees Saturday (70s to low 80s) across the interior and remain relatively stable in that range through the remainder of the forecast period. As mentioned in the short term discussion, upper level troughing will allow the marine layer to deepen, bringing daily coastal drizzle and allowing for improved overnight humidity recoveries. This will slightly reduce fire weather concerns across the interior Bay Area with ERC values (measure of how much energy is available for a fire) to drop and fuel moistures to rise slightly. As the upper level trough deepens next week, the GFS shows potential for rain to develop across northern CA. This is expected to remain well north of our CWA with only 2 out of 30 GFS ensemble members showing more than a tenth of an inch at STS next week (4 out of 30 show a trace at STS, 24 out of 30 show nothing at STS). The CPC 6-10 day outlook shows near to below normal temperatures and a chance for above normal precipitation continuing through September 13th.
(06z TAFS) Issued at 929 PM PDT Wed Sep 3 2025
Currently a mixed bag of IFR-VFR at the terminals with high clouds streaming in from a low pressure system in the Eastern Pacific Ocean. Moderate confidence in IFR/MVFR ceilings returning to most of the terminals tonight with confidence lowering the farther inland the terminal is. The pattern will change through the TAF period as the longwave upper-level ridging shifts east from approaching upper-level shortwave troughing. This will allow the marine layer to deepen and penetrate farther inland tomorrow night.
Vicinity of SFO, Currently VFR with westerly flow. Moderate confidence on the return of a ceiling (likely on the cusp of IFR/MVFR) to the terminal tonight. Westerly winds will prevail through the TAF period.
SFO Bridge Approach, Similar to SFO.
Monterey Bay Terminals, Currently IFR with westerly flow at MRY and MVFR with northwesterly flow at SNS. Brief VFR is expected tomorrow afternoon with low stratus sticking close to the coast.
(tonight through next Tuesday) Issued at 929 PM PDT Wed Sep 3 2025
Moderate to fresh northwesterly breezes will prevail through Saturday, slowly diminishing into Sunday. Locally strong gusts are expected along the coastal jet regions through the week. Moderate seas will prevail through the week.
Ca, None. PZ, Small Craft Advisory from 3 PM Thursday to 3 AM PDT Friday for Pt Pinos to Pt Piedras Blancas 0-10 nm.
