612 FXUS66 KMTR 081134 AFDMTR Area Forecast Discussion National Weather Service San Francisco CA 434 AM PDT Tue Jul 8 2025 ...New AVIATION... .KEY MESSAGES... Updated at 118 AM PDT Tue Jul 8 2025 - One more day of cool conditions before warmer temperatures return Wednesday through the weekend, with patchy Moderate HeatRisk across the Bay Area and Central Coast. - Localized elevated fire weather threat Wednesday through the weekend across the higher elevations. - Slight risk (20-40% probability) of extreme heat in the far interior portions of the Bay Area and Central Coast July 15-17. && .SHORT TERM... Issued at 118 AM PDT Tue Jul 8 2025 (Today and tonight) Marine layer clouds blanket the coast and are expanding into the inland valleys through the rest of the morning, with coastal drizzle possible through the morning hours. Low temperatures hover in the upper 40s to the middle 50s in the lower elevations, and up to the lower 60s in the highest peaks. An upper level low pressure system off the California coast continues to diminish and drift northwards, but it will provide us one more day of temperatures cooler than seasonal averages, with highs ranging from the middle 70s to lower 80s inland, up to the lower 90s in the warmest spots of southern Monterey and San Benito counties, into the middle 60s to middle 70s along the Bays, and into the upper 50s to the lower 60s along the Pacific coast. The onshore winds this afternoon and evening will be lighter than those seen yesterday, partially as a result of a relaxing pressure gradient aloft from the weakening low, but gusts around 20 mph are still possible through the gaps, passes, and the Salinas Valley. && .LONG TERM... Issued at 118 AM PDT Tue Jul 8 2025 (Wednesday through Monday) The dissipating upper level low will move inland near the California- Oregon border and allow a ridge centered over the Desert Southwest to expand into southern California, where heat products will go into effect starting Wednesday morning. Our part of the state will still experience a warming trend, with Wednesday`s highs rising to the 80s inland with the warmest spots in southern Monterey and San Benito counties reaching the upper 90s. Ensemble model cluster analysis has begin homing in on the Bay Area and Central Coast seeing more zonal flow as the heat peaks on Thursday and Friday, moderating the heat impacts as the southern part of the state swelters. The inland valleys see highs in the middle 80s to middle 90s on both days, while the warmest interior locations see temperatures rising up to a few degrees above 100. In terms of HeatRisk, patches of Moderate HeatRisk are expected on Thursday and Friday across the interior North Bay, East Bay, and South Bay, in addition to the Santa Lucia mountains and the southern tip of San Benito County. Remember to take frequent cooling breaks and drink plenty of water if participating in outdoor activities on both days. Temperatures for the upcoming weekend will cool slightly to the lower 80s to lower 90s in the interior Bay Area with an shortwave trough coming through the West Coast, while the interior Central Coast remains rather warm with temperatures in the 90s. Winds remain light and onshore through the weekend with locally breezier winds through the gaps, passes, and the Salinas Valley. Further afield, longer term outlooks show a lean towards temperatures above seasonal averages into the third week of July. Small fuels have effectively cured and large fuels are continuing to cure across the region as the dry weather continues, with further drying expected as the temperatures warm Wednesday through the weekend. Localized fire weather threats are possible, particularly in higher elevations above marine layer influence. Extreme caution is advised if participating in outdoor activities involving open flames and sparks, noting that most wildfires are started by human activity. One less spark, one less wildfire! && .AVIATION... (12Z TAFS) Issued at 422 AM PDT Tue Jul 8 2025 A mix of MVFR/IFR ceilings with a robust marine layer and onshore flow combined with onshore SFO/WMC pressure gradient around +5. Expect a steady presence of stratus along the coast with VFR returning by late morning, similar to yesterday. Vicinity of SFO...MVFR ceilings are expected to persist with a chance of occasional IFR ceilings with low confidence of if/when timing may be. Expect a steady fetch of onshore flow becoming breezy through the afternoon into the early evening hours. Stratus will return later tonight, likely around midnight. SFO Bridge Approach...Similar to SFO. Monterey Bay Terminals...MVFR/IFR ceilings will persist through the morning hours with some clearing expected, however stratus will remain close to the coastline over the water through most of the day. MVFR/IFR ceilings will return around sunset when breezy onshore flow starts to ease. && .MARINE... (Today through Sunday) Issued at 302 AM PDT Tue Jul 8 2025 Light to moderate southerly winds will persist today and tonight with moderate seas. Winds gradually increase out of the northwest on Wednesday with stronger winds by Thursday, along with building seas becoming rough. && .MTR WATCHES/WARNINGS/ADVISORIES... CA...None. PZ...None. && $$ SHORT TERM...DialH LONG TERM....DialH AVIATION...JM MARINE...JM Visit us at www.weather.gov/sanfrancisco Follow us on Facebook, X, and YouTube at: www.facebook.com/nwsbayarea x.com/nwsbayarea www.youtube.com/nwsbayarea