996 FXUS66 KMTR 281030 AFDMTR Area Forecast Discussion National Weather Service San Francisco CA 230 AM PST Sat Feb 28 2026 ...New SHORT TERM, LONG TERM... .KEY MESSAGES... Updated at 229 AM PST Sat Feb 28 2026 - Well above normal temperatures today - Slight chance (15-25%) for rain with embedded thunderstorms possible today in the North Bay - Slight cooling trend with light rain likely in the North Bay Sunday - Above normal temperatures with offshore flow next week && .SHORT TERM... Issued at 229 AM PST Sat Feb 28 2026 (Today and Sunday) The 00Z sounding observed an 850 mb temperature of 15.35 degrees Celsius which is the second highest (16.3 degrees Celsius in 1986) for the date and time. With a warm air mass in place, well above normal temperatures are expected today. Surface high pressure in the Intermountain West and a coastal trough off the California Coast will generate light offshore flow. So not only will we be warm, but our natural air conditioning (the sea breeze) will be turned off. To limit heat-related impacts, people should increase water intake, reduce time spent outdoors or stay in the shade when the sun is the strongest, and open windows at night and use fans to bring cooler air inside buildings. We will begin to feel the influence of an upper-level low in the Eastern Pacific Ocean today, as alluded to by the high clouds that are beginning to stream in. The first of two embedded shortwaves will swing through the region today, bringing with it a slight (15-25%) chance for rain with embedded thunderstorms possible. The highest probability of occurrence (still low) will be in the North Bay with ensemble members continuing to show little to no accumulation today. The second embedded shortwave will swing through on Sunday, bringing us another chance for rain and thunderstorms. Measurable rainfall (0.01 inches or greater) is now looking likely (60% chance) on Sunday for the North Bay - especially in the higher terrain. If the criteria gets bumped up to a wetting rain (0.10 inches or greater), the areal extent is significantly reduced to only the Mayacamas Mountains and Hills of Western Sonoma County. Thunderstorm chances will remain low (20% or less) through this upper-level low. The three ingredients needed for thunderstorm development are lift, instability, and moisture. While all will be present, they are not expected to overlap favorably in space and/or time. Sensible weather wise, Sunday will be about 10 degrees cooler than today. For locations south of the Golden Gate Bridge, drizzle will be possible along the coast and in the higher terrain. && .LONG TERM... Issued at 229 AM PST Sat Feb 28 2026 (Monday through Friday) The upper-level low will begin to fill as it moves through the region on Monday. As it does so, rain chances will be renewed yet again Monday morning with light rain possible for the North Bay and drizzle possible for coastal and higher terrain locations south of the Golden Gate Bridge. Upper-level shortwave ridging will begin to nose in from the Eastern Pacific Ocean the latter half of Monday. The pattern will remain progressive with an upper-level shortwave trough on the ridge's heels. There is uncertainty on the location and the evolution of this feature, and to some extent the strength. It can be discerned though that this pattern will be conducive for warm and dry conditions with offshore flow, especially Wednesday through Friday. Even though we are in Winter with rainfall totals right around normal for this time of year, it's never too soon to think ahead towards "fire season". One side of the fire triangle (fuels) is right around average for this time of year; however, Energy Release Components (ERC), Burning Indices (BI), and 100 hour dead fuel moisture are all expected to be above average by early next week. While fuels are still projected to remain within the "significant spread unlikely" range, this is still something to be made aware of as receptive vegetation will have the potential to burn, especially on any wind-and-terrain aligned starts. As always, exercise fire weather safety no matter the time of year. && .AVIATION... (06Z TAFS) Issued at 930 PM PST Fri Feb 27 2026 Widespread VFR continues into the night with high clouds continuing to build. Winds become lighter into the night with directions at most sites going variable. Pockets of inconsistent mist will be possible at STS, but look to erode into the late morning, leading to widespread VFR. Winds build slightly into Saturday afternoon, but become weak again that evening and night. Vicinity of SFO...VFR through the TAF period. Expect light to moderate north winds into the night before winds become light and variable. West winds build again into Saturday afternoon and last well into that night. SFO Bridge Approach...Similar to SFO. Monterey Bay Terminals...VFR through the TAF period. Winds become light into the night. Southeast winds build for SNS into the early morning, but switch to northwest winds Saturday afternoon while MRY goes more westerly. Winds become light again that night. && .MARINE... (Tonight through next Thursday) Issued at 930 PM PST Fri Feb 27 2026 Light northerly winds continue across the waters through the weekend. Drizzle is possible across the northernmost zones Saturday and Sunday morning and again into early next week. Low to moderate seas continue into next week with stronger winds arriving in the mid week. && .CLIMATE... Issued at 1116 PM PST Fri Feb 27 2026 The following are the record high temperatures at the long term sites for Saturday, Feb 28th. Location Feb 28th Record High Santa Rosa 93 in 1923 San Rafael 78 in 2025 Kentfield 78 in 1929, 1923 Napa 81 in 1929 Richmond 77 in 1986 Livermore 82 in 2022 San Francisco 76 in 1992, 1986 SFO Airport 73 in 1959 Redwood City 77 in 2025 Half Moon Bay 74 in 1954 Oakland Museum 75 in 2025 San Jose 77 in 2025, 1926 Salinas Airport 81 in 2022 && .MTR WATCHES/WARNINGS/ADVISORIES... CA...None. PZ...None. && $$ SHORT TERM...Sarment LONG TERM....Sarment 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