, Issued at 1201 PM PDT Wed Sep 30 2026 (This evening through Thursday night)
Mostly clear skies predominate with limited patches of stratus along the Big Sur Coast. Tonight the stratus deck will come into the North Bay valleys, the SF and Monterey Bay regions, and the northern Salinas Valley, with expansion into the interior not expected tonight. Today marks the first day of warm temperatures as a ridge sets up over the Western United States, with highs ranging from the middle 80s to middle 90s in the inland valleys, up to the upper 90s for the warmest spots in the interior Central Coast, the middle 70s to middle 80s along the Bays, and the middle 60s to the lower 70s along the Pacific coast. Highs will be very similar on Thursday. Winds will be relatively light with an onshore breeze developing in the afternoon and evening hours, and a push of offshore wind in the higher elevations of the North and East Bay tonight through Thursday morning. This morning gusts of 48 mph were reported on Mount St. Helena and 46 mph at the Santa Fe Geothermal station within the Mayacamas, with other exposed ridges in the interior North and East Bays reporting peak gusts in the 25-35 mph range. Expect similar gusts tonight, resulting in poor overnight humidity recoveries and elevated fire weather conditions.
Areas of Moderate HeatRisk are starting to pop up across the inland regions, and expand across the inland regions of the East Bay, South Bay, and the Central Coast on Thursday. These correspond to a moderate risk of heat-related illnesses for sensitive populations, including children, the elderly, pregnant women, people with chronic illnesses, and people who work or live outdoors without access to adequate cooling or hydration. Follow these tips to avoid heat exhaustion and heatstroke:
* Stay hydrated and drink plenty of fluids. * Wear lightweight, light-colored clothing. * Reduce time spent outdoors or stay in the shade. * Never leave people or pets unattended in vehicles. * Use sunscreen if going to the coast or the pool.
Minor coastal flooding is possible across the bayshore locations of San Francisco Bay, San Pablo Bay, and Monterey Bay around high tide. Up to 1.2 feet of inundation above normally dry land is expected, including up to 0.7 ft of surge caused by thermal expansion and sea level rise since the sea level datum (basically the point where we define as "sea level") was set in the 1983-2001 period. At the San Francisco tidal gauge, high tide is expected to be 1.2 ft above normal (7.03 ft MLLW) at 2:10 PM Wednesday 9/30 and 1.1 ft above normal (6.92 ft MLLW) at 2:58 PM on Thursday 10/1.
..issued at 1201 PM PDT Wed Sep 30 2026 (Friday through next Tuesday)
The ridging remains rather resilient through the seven-day outlook and temperatures remain warmer than the seasonal average through the week. A notable warming trend will take place over the weekend with temperatures warming to the 90s into the triple digits (as warm as 102 degrees in the warmest spots of interior Monterey and San benito Counties). Moderate HeatRisk will become widespread across the inland locations, and there is a decent chance (40-60% probability) that areas within the interior East Bay, South Bay, Santa Lucia range, and interior Central Coast reach Major HeatRisk. That would correspond to a more widespread risk for heat-related illnesses for most people, and if this scenario remains on track through the next day, Heat Advisories for these areas are likely. Longer-range outlooks suggest that temperatures above seasonal averages are very likely (70-90% probability) into the second week of October, and this is supported by ensemble model cluster analysis, where all clusters agree on keeping some form of ridging around across the first week of October.
(18z TAFS) Issued at 1025 AM PDT Wed Sep 30 2026
Developing marine layer is battling building high pressure over the region. As such, the inversion height is compressed leading to low CIGs along the coast. That being said, expecting VFR through early this evening. CIGs return early for MRY/SNS and later for N Bay and in SF Bay. Moderate conf for fog development tonight given the shallow nature of the marine layer.
Vicinity of SFO, VRF through this evening. CIGs slowly redevelop inside SF Bay impacting OAK and SFO 07-09Z timeframe. Lower CIGs linger into the AM rush for Thursday.
SFO Bridge Approach, Less chc for late night CIGs, but still expecting some around the approach zone.
Monterey Bay Terminals, VFR through this afternoon, but CIGs lurking outside of MRY Bay will return early this evening. High conf on fog impacts by Thursday morning.
(today through Monday) Issued at 1025 AM PDT Wed Sep 30 2026
Northerly winds will continue to ease through the day, but still hazardous with moderate to strong breezes. Strongest winds are over the outer waters north of Point Reyes. Conditions will improve later this week and weekend as northwesterly breezes diminish to become gentle to moderate. Rough to very rough seas today will subside to moderate by Friday.
Ca, Coastal Flood Advisory until 5 PM PDT Thursday for CAZ006-506- 508-529-530.
PZ, Small Craft Advisory until 3 AM PDT Thursday for Pigeon Pt to Pt Pinos 10-60 NM-Pt Arena to Pt Reyes 10-60 NM.
