, Issued at 1237 AM PDT Fri Oct 2 2026 (Today and tonight)
The 00Z sounding observed an 850 mb temperature of 21.75 degrees Celsius and a 500 mb height of 5900 meters; both of these are above the 90th percentile of 20.6 degrees Celsius and 5883 meters, respectively. Upper-level ridging across the Southwest will bring temperatures 10 to 15 degrees above normal to the interior Friday, resulting in areas of moderate HeatRisk. Subsidence aloft will compress the marine layer, keeping it confined to the coast and supporting fog development. Above the marine layer in the higher terrain, elevated fire weather conditions continue from hot and dry conditions with offshore flow overnight. Minor coastal flooding for bayshore locations along the San Francisco Bay, San Pablo Bay, and Monterey Bay will occur during high tide Friday afternoon.
..issued at 1237 AM PDT Fri Oct 2 2026 (Saturday through Thursday)
A Heat Advisory is in effect for most of the interior from 11AM Saturday through 10PM Sunday. This covers the peak of the heat as upper-level longwave ridging drifts in from the Eastern Pacific Ocean. A compressed marine layer around 500 feet is currently forecast during this time; however, if it erodes from offshore flow or clouds fail to develop, the coast will be hotter than forecast. Upper-level shortwave troughing will undercut the ridge Sunday into Monday with the ridge rebounding across the West Coast Tuesday into Wednesday. No matter how you slice it, it is going to be hot for the next week with temperatures 15 to 20 degrees above normal and moderate to major HeatRisk across the interior. A compressed marine layer, weaker than normal onshore flow, and minimum temperatures well above normal will bring less relief than normal overnight. This will also keep elevated fire weather conditions across the higher terrain. Even though we are nearing the end of our heat season, cumulative heat impacts are expected across the interior. With all that being said, no records are in jeopardy as October is one of the hottest months for the region. Finally by Thursday, 44% of global ensemble clusters begin to show signs of a pattern change via falling heights.
(18z TAFS) Issued at 1047 AM PDT Fri Oct 2 2026
VFR conditions returning to the region with the exception of HAF where LIFR persists. Onshore winds are forecast to increase this afternoon, yet will be weaker than previous days as high pressure builds over the region. Expecting SCT/BKN high clouds through much of the day today with them moving east of the region tomorrow. Winds ease late this evening with sub-IFR conditions most likely along the coast and around the Monterey Bay terminals late tonight into early tomorrow morning.
Vicinity of SFO, VFR. Onshore winds will increase this afternoon between 21Z-00Z. Winds ease late in the evening with a 10-20% probability of sub-MVFR (as low as LIFR) between 10Z-16Z Saturday based off of the NBM. Thus, have left ceilings/fog out of the forecast for both SFO and OAK.
SFO Bridge Approach, Similar to SFO.
Monterey Bay Terminals, VFR. Generally light onshore winds will increase this afternoon before easing after sunset. Moderate confidence for sub-MVFR and as low as LIFR conditions to return overnight, generally a 40-55% probability from 02Z-15Z Saturday. Any low clouds and fog that develops will dissipate between 15Z-18Z.
(today through Wednesday) Issued at 1047 AM PDT Fri Oct 2 2026
A gentle to moderate northerly to northwesterly breeze will continue through the weekend and into next week. Low to moderate seas will also persist into early next week.
Ca, Coastal Flood Advisory until 6 PM PDT this evening for CAZ006- 506-508-529-530.
Heat Advisory from 11 AM Saturday to 10 PM PDT Sunday for CAZ503- 504-508-510-512>518.
PZ, None.
