489 FXUS66 KMTR 090802 AFDMTR Area Forecast Discussion National Weather Service San Francisco CA 102 AM PDT Wed Jul 9 2025 ...New SHORT TERM, LONG TERM... .KEY MESSAGES... Updated at 101 AM PDT Wed Jul 9 2025 - Warming trend begins today through the weekend, with patchy Moderate HeatRisk across the Bay Area and Central Coast Thursday and Friday. - Localized elevated fire weather threat starting today through the weekend across the higher elevations. && .SHORT TERM... Issued at 101 AM PDT Wed Jul 9 2025 (Today and tonight) Satellite imagery shows widespread marine layer stratus across the valleys of the Bay Area and Central Coast, as data from the Fort Ord profiler shows the top of the marine layer becoming more diffuse while rising to at least 3000 feet over the last evening. Low temperatures this morning will hover in the lower to middle 50s in the lower elevations, and as high as the lower 60s in the highest peaks. Today marks a pattern change from the cooler regime of the last few days to a warming pattern that (spoiler alert) looks to set up for the rest of the week. The upper level low that brought us the robust marine layer and the cool temperatures is dissipating while it meanders towards landfall in the North Coast. This will allow an ridge that`s set up over the desert Southwest to edge into the state while a synoptic high pressure system develops in the east Pacific, causing temperatures to warm. Temperatures will range from the upper 70s to the middle 80s inland, with the warmest spots in southern Monterey and San Benito Counties reaching the upper 90s, while locations on the Bays reach highs in the upper 60s and the 70s. The marine layer will compress, but the coastal areas should remain rather cool with highs in the upper 50s to the lower 60s. Some elevated fire weather threat is forecast to develop today across areas above and inland of the marine layer`s influence. The combination of dry daytime humidities of around 15-30% and localized gusts to 30 mp will be the main factors behind the elevated threat. However, the winds will remain onshore, leading to the fire weather threat being diurnally driven, especially in the foothills where lighter winds and good overnight recoveries are expected each night. && .LONG TERM... Issued at 101 AM PDT Wed Jul 9 2025 (Thursday through Tuesday) Temperatures continue to rise on Thursday and Friday as the high pressure systems become more established, with the inland valleys seeing 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. 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. As a very weak upper level disturbance passes through the state this weekend, temperatures 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. The pattern will otherwise remain rather stable through the early part of next week, with warm inland temperatures, cool coastal temperatures, light onshore winds, and localized elevated fire weather threat in the interior developing each afternoon. && .AVIATION... (06Z TAFS) Issued at 1002 PM PDT Tue Jul 8 2025 IFR and MVFR CIGS are building along the coast and have filled at HAF as well as the SF Bay And Monterey Bay terminals. Winds will stay light to moderate through the night as widespread IFR CIGs affect the region with MRY and HAF falling to LIFR into the early morning. Inland clearing begins in the mid morning with most TAF sites going VFR in the late morning and early afternoon. The exception will be HAF, which keeps CIGs through the TAF period. Winds look to stay light to moderate through the morning and increase into late Wednesday morning and afternoon. Expect winds to reduce into Wednesday evening with CIGs slower to move inland that night. Vicinity of SFO...IFR lasts into the late morning. Winds are reducing and look to stay light through the night and much of the morning. Expect CIGs to erode into the late morning as moderate to breezy west winds arrive. These winds reduce into late Wednesday evening. SFO Bridge Approach...Similar to SFO. Monterey Bay Terminals...IFR CIGs have filled over the terminals and winds are reducing, becoming light. MRY sees winds become very light into the night and CIGs fall to LIFR with some pockets of mist and drizzle in the area into early Wednesday. Winds become moderate into mid to late Wednesday morning as CIGs erode over the terminals. && .MARINE... (Tonight through next Monday) Issued at 900 PM PDT Tue Jul 8 2025 Expect light to moderate winds with weak seas into Wednesday. Winds will strengthen and turn more northerly by Wednesday afternoon and continue strengthening, becoming fresh to strong on Thursday and into the weekend. Significant wave heights will be rough to very rough Thursday through Saturday for the outer waters. && .MTR WATCHES/WARNINGS/ADVISORIES... CA...None. PZ...Small Craft Advisory from 3 PM this afternoon to 3 AM PDT Thursday for Pt Arena to Pt Reyes 0-10 nm-Pt Pinos to Pt Piedras Blancas 0-10 nm. Small Craft Advisory from 3 PM this afternoon to 3 PM PDT Thursday for Pigeon Pt to Pt Pinos 10-60 NM-Pt Arena to Pt Reyes 10-60 NM. && $$ SHORT TERM...DialH LONG TERM....DialH AVIATION...Murdock MARINE...Murdock 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