, Issued at 1236 PM PDT Mon Oct 5 2026 (This evening through Tuesday night)
Stratus clouds lurk at the immediate coast, associated with a shallow marine layer around 500-1000 feet thick, but the rest of the region remains hot through the next couple of days as ridging persists across the western United States, ridging which is helping compress the marine layer and preventing any substantial overnight relief from reaching the higher elevations. To our northeast, high level clouds and convective remnants, associated with a puff of moisture riding an embedded low in the larger scale ridging, linger over the northern Sierra Nevada range and into the northern sections of the Great Basin. This time yesterday, that puff of moisture was streaming over the Bay Area, resulting in streaming high clouds that contributed to some cooler (relatively speaking) conditions than the expectation. Today the skies remain clear, and it's possible for today's high temperatures to overperform yesterday's, especially across the North Bay. High temperatures today and Tuesday range from the middle 90s to near 106 across the inland valleys, the middle 80s to the lower 90s near the Bays, and the upper 60s to the lower 70s along the Pacific coast. Mild overnight lows in the higher elevations, ranging from the upper 60s to the middle 70s, along with weak onshore flow will limit overnight recoveries.
A Heat Advisory remains in effect for the interior regions, excluding the coastal strip and the northern Salinas Valley, as widespread Moderate HeatRisk blankets the interior, corresponding 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. In addition, many of the higher elevations are seeing Major HeatRisk, corresponding to a high risk for heat-related illnesses for anyone without hydration or cooling. 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.
..issued at 1236 PM PDT Mon Oct 5 2026 (Wednesday through next Sunday)
Ridging persists for the next few days and the Heat Advisory has been extended to Thursday night for the inland and Bayshore regions. Temperatures across the inland valleys remain in the middle 90s to near 105 into Thursday; despite a couple of degrees of cooling on Thursday, hazardous heat lingers across the region and widespread Moderate HeatRisk persists in the inland regions. Patches of HeatRisk linger into Friday across the interior, and the Heat Advisory may need to be extended if confidence in heat-related impacts increases.
Towards the latter part of the seven day outlook, uncertainty in the forecast increases as the ridge starts to break down and a trough begins to develop along the West Coast. Ensemble model cluster analysis suggests a split between solutions that bring something akin to an inside slider to the Great Basin for the upcoming weekend and those that keep the ridging in play. The inside slider solution slightly dominates the cluster space at this time, but we will wait for the model trend to become clearer before committing to a particular solution.
(00z TAFS) Issued at 443 PM PDT Mon Oct 5 2026
Currently VFR everywhere except HAF where LIFR conditions have developed. Largely expecting a shallow 500 ft marine layer to remain in place today which will see a return of fog and IFR-LIFR conditions to the coast. Guidance suggests some potential for lower ceilings/reduced visibility to reach STS, OAK, and SFO but confidence is low that this will occur. Conditions improve by late tomorrow morning with VFR persisting through the remainder of the day. Onshore winds remain between 10 to 16 knots during the day tomorrow with lighter, variable winds overnight.
Vicinity of SFO, VFR. Onshore winds will diminish overnight before increasing again during the day tomorrow. There is some potential for MVFR conditions to develop between 09-17Z but confidence is on the lower end. The shallow depth of the marine layer should keep stratus/fog confined directly to the coastline and prevent it from reaching SFO,
SFO Bridge Approach, Similar to SFO.
Monterey Bay Terminals, Moderate onshore winds diminish this evening with light, variable winds overnight. The stratus deck is slowly expanding along the Monterey Peninsula coastline. It should reach MRY around 02Z and SNS closer to 06Z. There is the potential for it to arrive slightly earlier/later depending on how fast it is able to spread. Fog becomes more likely after 06Z with highest confidence in fog developing at MRY over SNS. Last night fog temporarily developed at MRY but it looks to be more widespread/consistent across the Monterey Peninsula tonight.
(tonight through next Saturday) Issued at 443 PM PDT Mon Oct 5 2026
Gentle to moderate northwesterly breezes and slight to moderate wave heights persist into midweek. Winds increase and wave heights build, seas becoming rough across the outer waters, Friday into the weekend. Additionally, increase southerly swell will impact the coastal waters beginning Tuesday night and into the upcoming weekend.
Ca, Heat Advisory until 10 PM PDT Thursday for CAZ503-504-506-508- 510-512>518.
PZ, None.
