763 FXUS66 KMTR 271803 AFDMTR Area Forecast Discussion National Weather Service San Francisco CA 1103 AM PDT Sun Apr 27 2025 ...New AVIATION... .SYNOPSIS... Issued at 1205 AM PDT Sun Apr 27 2025 Light showers focused on the Central Coast continue through the morning. A pattern change will bring warmer and drier weather through the work week. && .UPDATE... Issued at 904 AM PDT Sun Apr 27 2025 Drizzly conditions and light rain showers continue across the Bay Area and Central Coast through this afternoon. A look at 36 hour precipitation totals shows the Santa Lucia Range as the big winner with between 0.3"-0.6" observed from this event. Elsewhere, totals ranged from a few hundredths of an inch to two tenths of an inch with locally higher amounts across the elevated terrain. Additional rainfall today is expected to be light, amounting to only a few hundredths of an inch. && .SHORT TERM... (Today and tonight) Issued at 1205 AM PDT Sun Apr 27 2025 KMUX shows light rain falling throughout the majority of Monterey County. This includes the Big Sur International Marathon course where runners will begin loading shuttles in just 3 hours or so. A nearly cut-off low pressure system has drifted towards the CA/NV border, and the Bay Area is now firmly in the back-side environment. The dynamics are a bit unusual, however. A moisture plume is keeping the PWAT above 150% of normal, despite the northerly winds which veer offshore with height. There is also some indication of fr0ontogenesis with warm air advection present at 700 mb. Thunderstorms never materialized on Saturday, and the chance continues to diminish. All signs point to the rain tapering off through the morning with skies starting to clear in the evening. Temperatures will remain in the 50s and 60s due to overcast skies and a lingering cold air mass. There is a good chance for fog during the Monday commute as building high pressure causes the skies to clear over the still cool and humid surface. && .LONG TERM... (Monday through Saturday) Issued at 1205 AM PDT Sun Apr 27 2025 After any fog mixes out late Monday morning, it will turn into a beautiful day with plenty of sunshine and temperatures up to 10 degrees warmer than the weekend. The good weather will continue through the work week as a ridge builds over the west coast. Mid week looks to be the warmest with inland highs in the mid to upper 70s. A shallow marine layer will keep coastal areas in the low 60s, but the coastal clouds shouldn`t last all day. Most guidance indicates the pattern will become unsettled again by Friday or Saturday as some combination of a cut-off low and/or mid-level trough bring back overcast skies, cooler temperatures, stronger wind, and a slight chance for rain next weekend. && .AVIATION... (18Z TAFS) Issued at 1103 AM PDT Sun Apr 27 2025 Impacts of upper low moving to our east is still impacting the terminals and airspace with extensive low clouds over the region this morning with bases roughly 1500-2500 feet. Radar showing lingering showers from Santa Clara Valley southward through Monterey county with KMRY the most likely to hold onto lingering showers or drizzle through early afternoon. Expect gradual clearing and lifting of cloud bases after 21z this afternoon with light nw winds. Enough lingering moisture and cyclonic flow for low clouds to stay in place overnight with higher confidence for skies clearing with VFR conditions beyond 18z Monday. Vicinity of SFO...Improving conditions after 21z with cigs mixing and lifting before returning overnight through Monday morning. Higher confidence for clearing skies and a return of VFR after 18z Monday. SFO Bridge Approach...Similar to SFO. Monterey Bay Terminals...Lingering showers and drizzle through early afternoon. High confidence for MVFR cigs to return overnight through Monday morning with VFR conditions likely after 18z Monday. && .MARINE... (Today through Friday) Issued at 904 AM PDT Sun Apr 27 2025 Northwest winds will be gusty due to a high pressure system building over the offshore waters through early week, winds will also result in hazardous seas across the outer coastal waters. From mid to late week surface high pressure will gradually weaken while an upper level trough will move in from the northwest. By late week another upper level trough from the northwest will approach the coastal waters and bays. && .MTR WATCHES/WARNINGS/ADVISORIES... CA...None. PZ...Small Craft Advisory from 3 PM this afternoon to 9 PM PDT this evening for Mry Bay. Small Craft Advisory until 3 AM PDT Monday for Pt Arena to Pt Reyes 0-10 nm-Pt Pinos to Pt Piedras Blancas 0-10 nm. Small Craft Advisory from 3 PM to 9 PM PDT Monday for Pt Arena to Pt Reyes 0-10 nm-Pt Pinos to Pt Piedras Blancas 0-10 nm. Small Craft Advisory until 9 PM PDT this evening for Pigeon Pt to Pt Pinos 0-10 nm-Pt Reyes to Pigeon Pt 0-10 nm. Small Craft Advisory until 9 PM PDT Monday for Pigeon Pt to Pt Pinos 10-60 NM-Pt Arena to Pt Reyes 10-60 NM. && $$ SHORT TERM...Flynn LONG TERM....Flynn AVIATION...RW MARINE...RW 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