217 FXUS66 KMTR 081138 AFDMTR Area Forecast Discussion National Weather Service San Francisco CA 438 AM PDT Fri Aug 8 2025 ...New AVIATION... .KEY MESSAGES... Updated at 428 AM PDT Fri Aug 8 2025 - Moderate HeatRisk Friday through Monday for portions of North, East, and South Bay counties and interior Monterey and San Benito counties. - Seasonally warm conditions through the early part of next week. - Elevated fire weather concerns given the warming and drying trend coupled with daily afternoon/evening breezes. && .SHORT TERM... Issued at 428 AM PDT Fri Aug 8 2025 (Today and tonight) Satellite imagery this morning paints a different picture compared to yesterday. The main feature being the intrusion of stratus along the Central Coast and its interior valleys, while stratus hugs Marin, San Francisco, and San Mateo counties. The marine layer looks to be around 1000ft based of the Fort Ord profiler which matches some of the guidance for this morning. Farther north it appears to be closer to 500-1000ft, which is likely why we haven't seen stratus seep into the North Bay this morning. With the marine layer being shallow, expect stratus to retreat to the coast leaving much of the area with sunny skies by mid to late morning. These conditions combined with high pressure building into the region will lead to warmer conditions today. For those inland and less influenced by the marine layer, look for temperatures to soar into the 90s, with interior locations of East Bay, Napa, San Benito, and Monterey potentially cracking 100 degrees. Moderate HeatRisk is a bit more widespread given the slight increase in temperatures for these areas. With that being said, like yesterday I said in yesterday's extended discussion, if you're going to be outdoors, be sure to practice heat safety. Some pro tips include: wearing sunscreen, taking breaks, staying hydrated, and looking before you lock your vehicle. && .LONG TERM... Issued at 428 AM PDT Fri Aug 8 2025 (Saturday through Thursday) Upper level ridging builds over the weekend and holds into early next week. Patches of Moderate HeatRisk are expected for portions of the East, South, and North Bay while Minor HeatRisk is expected elsewhere. For those who have to work or are looking to enjoy the outdoors, be sure to practice heat safety. Wear sunscreen, take breaks, hydrate, and look before you lock your vehicle. Additionally, if you're seeking relief at the beach be mindful of an energetic surf zone with increased rip currents and sneaker waves. The ridge looks to break down Tuesday into Wednesday, as an upper level trough drops in from the north. This will lead to decreasing temperatures, for interior locations. && .AVIATION... (12Z TAFS) Issued at 435 AM PDT Fri Aug 8 2025 Currently a mixed bag of LIFR-VFR at the terminals with a marine layer of about 1,400 feet. High confidence in widespread VFR by the afternoon with low stratus sticking close to the coast. With very little change in the overall pattern through the TAF period, expect similar conditions tonight as what is underway. Vicinity of SFO...Currently MVFR with westerly flow. A very generous MVFR ceiling is being reported with a majority of the stratus hugging the San Francisco Peninsula Coast. High confidence (80%) on VFR prevailing through the TAF period. Winds will back (turn counterclockwise) through the morning before the afternoon sea breeze kicks in. SFO Bridge Approach...Similar to SFO. Monterey Bay Terminals...Currently LIFR with southerly flow at MRY and IFR and calm at SNS. High confidence (75%) on ceilings on the cusp of LIFR/IFR returning to both terminals tonight. && .MARINE... (Today through Wednesday) Issued at 428 AM PDT Fri Aug 8 2025 Fresh to strong northwesterly breezes will wane through Saturday morning with a gentle to moderate breeze prevailing through Tuesday. Moderate to rough seas over the weekend will abate to widespread moderate seas by Monday. && .FIRE WEATHER... Issued at 1004 AM PDT Thu Aug 7 2025 Elevated fire weather concerns will persist through the weekend. The warming and drying trend combined with daily afternoon/evening wind pushes will yield near critical fire weather conditions. Simply put, conditions are ripe for an uptick in grass fires/small veg fires the next few days. Inland gaps/passes and higher terrain will be highest at risk given the lack of marine layer/coastal moisture influence. MM && .MTR WATCHES/WARNINGS/ADVISORIES... CA...None. PZ...Small Craft Advisory until 9 AM PDT Saturday for Pt Arena to Pt Reyes 10-60 NM. && $$ SHORT TERM...KR LONG TERM....KR AVIATION...Sarment MARINE...Sarment 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