, 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.
(06z TAFS) Issued at 947 PM PDT Mon Oct 5 2026
Stratus has settled in along the coastline and is trying to intrude into the North Bay/Golden Gate Gap areas. Confidence remains low that stratus will reach STS, SFO, or OAK but there remains a slight chance. Night shift will need to keep an eye as to if the Golden Gate Gap stratus intrusion is able to hold together and if it starts to push towards SFO/OAK. Model guidance is underdoing the amount of stratus along our coastline with HAF and MRY reporting LIFR conditions as of 4Z. Fog will set in along the coast overnight and impact HAF, MRY, and SNS. If stratus is able to reach STS, OAK, or SFO it is likely that temporary reductions in visibility/ceiling height to IFR-LIFR conditions will occur. Conditions improve mid to late morning with model guidance mixed as to when stratus will return tomorrow night. Satellite shows a swath of dry air pushing north to south towards our coastal waters which may impact our stratus chances for tomorrow night. Winds remain diurnally breezy with moderate onshore winds during the day and lighter, variable winds overnight.
Vicinity of SFO, VFR with a low potential for IFR-LIFR conditions overnight if the shallow marine layer/stratus deck is able to make it into the San Francisco Bay. Confidence remains low that stratus will make it to SFO but chances increase slightly (10-20%) between 12 to 18Z. Moderate onshore winds expected during the day with winds decreasing overnight.
SFO Bridge Approach, Similar to SFO.
Monterey Bay Terminals, LIFR conditions expected with fog to develop tonight. Visibilities drop to 1/2SM with the potential for dense (1/4SM) fog to develop. Moderate confidence that conditions will improve by 18Z but significant improvement may occur as late as 20Z. The caveat is the drier airmass moving in offshore, visible on satellite imagery, which may result in stratus/fog clearing slightly earlier than expected if the drier air makes it closer to shore. Light onshore winds continue at MRY through the day while moderate onshore winds return to SNS.
(tonight through next Sunday) Issued at 947 PM PDT Mon Oct 5 2026
A gentle to moderate northwesterly breeze continues through midweek with locally fresh gusts over the northern outer waters. Winds increase Friday into the weekend with near gale to gale force gusts likely. Seas will build in response to increasing winds and become rough. Additionally, southerly swell will impact the coastal waters starting Tuesday night with long period southerly swell increasing Friday into the weekend.
Ca, Heat Advisory until 10 PM PDT Thursday for CAZ503-504-506-508- 510-512>518.
PZ, None.
