FXUS66 KMTR 121733 AFDMTR Area Forecast Discussion National Weather Service San Francisco CA 1033 AM PDT Thu Jun 12 2025 ...New AVIATION, MARINE... .SYNOPSIS... Issued at 252 AM PDT Thu Jun 12 2025 The daily pattern of the return of marine layer clouds overnight through the morning hours, some coastal drizzle, and breezy afternoon onshore winds continues. Temperatures remain in the upper 50s and into the 60s at the coast, the 70 to 80s for areas more inland, and into the 90s for the far interior. Areas away from the marine layer continue to experience dry conditions, leading to some fire concerns as grasses and smaller plants continue to cure. && .SHORT TERM... (Today and tonight) Issued at 252 AM PDT Thu Jun 12 2025 For the 3rd night in a row there is a reduction in cloud cover across much of the area. The marine layer is around 2000ft and there is still a fair push of moisture inland from it, but the increased expansion of the marine layer has decreased the concentration of the moisture and made it slightly harder for cloud cover to form overland. This is coupled with the fact that low cloud transport over the marine environment is moving mostly north to south, and not much is turning towards the coast itself, also reducing our cloud cover. Pockets of fog and some areas of drizzle will still be possible along the San Mateo Coast and around the Monterey-Carmel-Pacific Grove area with slight chances around the SF Bay into the early morning. The reduced cloud cover will result in the warming trend for the slightly more inland areas to continue today, while the cloudier immediate coast stays cool and the far interior stays roughly the same(warm). Breezy to gusty winds are expected in the afternoon and into the evening, especially right along the dividing line between the cloudier to clearer environments. Cloud cover builds earlier this evening than Thursday night, with a better feed of cloud cover building in from the ocean than what we're seeing this morning. && .LONG TERM... (Friday through Wednesday) Issued at 252 AM PDT Thu Jun 12 2025 I'm struggling to find much remarkable about the next few days as the pattern remains fairly solid: -Cloudy on the coast -Breezy and some clearing for the afternoons -Warm days for the cloudless -Cool days for the cloudy The only true variations in temperatures and wind are going to be for the areas that are going to be on the edges of the cloud cover. So, we're having fun with microclimates and how short drives can mean the difference between putting the heater on or the air conditioning in the car! The pattern does look to change into the next work week! Models have been hinting at a trough pattern arriving sometime over the weekend for some time, but the passage has been delayed more and more with each update. This has been from a combo of momentum changes and a some different angling on the jet stream. For now, it looks like the trough will arrive on Monday, but there is still some potential for an even more delayed arrival. The tough itself will increase onshore flow and lead to widespread cooling, but only up to 5 degrees or so for daily highs, and even less so for overnight temps. Model agreement has improved on the post-trough passage environment, offering some reductions in onshore flow, but not so much going into ridging nor offshore flow. It will offer some slight warming, but as of the current forecast, nothing drastic. && .AVIATION... (18Z TAFS) Issued at 1032 AM PDT Thu Jun 12 2025 MVFR conditions prevail at some terminals this morning but are quickly returning to VFR as low clouds clear and retreat to the coast. Winds increase this afternoon with gusts up to 30 kt at SFO before easing late Thursday night and into Friday morning. IFR/MVFR conditions forecast to return late this evening for the Monterey Bay terminals and early Friday morning for the Bay Area terminals, generally moderate confidence. Low level winds shear continues to be in the TAFs for the North Bay tonight/Friday morning as winds at the surface go light and northwest winds up to 30 kt will prevail aloft. Vicinity of SFO...VFR conditions expected this afternoon with an increase in onshore winds with gusts up to 30kt. Winds will ease slightly overnight and into Friday morning, yet generally remain west-northwesterly. Moderate confidence for low clouds to return early Friday morning across the Bay Area terminals (generally MVFR but may drop to IFR). MVFR ceilings will return by late Friday morning or early afternoon with an increase of onshore flow once again. SFO Bridge Approach...Similar to SFO. Monterey Bay Terminals...VFR conditions expected this afternoon with an increase in onshore winds. Winds ease late this evening with moderate to high confidence of IFR/MVFR ceilings returning. && .MARINE... (Today through Tuesday) Issued at 1032 AM PDT Thu Jun 12 2025 Fresh to strong northwesterly breezes, near gale force gusts, and moderate to rough seas will prevail through Monday. Expect gale force gusts to develop near the coastal jet regions of Point Reyes and Point Sur during the afternoon and evening hours of today and again Friday. && .FIRE WEATHER... Issued at 252 AM PDT Wed Jun 12 2025 Areas not being reached by the marine layer continue to see dry conditions. Higher elevations, particularly in the Santa Lucias and in the Gabilan range, continue to see poor humidity retentions and recoveries. In fact, some locations are hitting single digit and lower teens for RH values. A few locations in the interior North Bay are seeing breezy north to northeast winds and these winds look to last into the morning which will increase drying in these areas. Winds will remain breezy each afternoon/evening through the Delta, and any inland gap or pass. The combination of dry fine fuels (grasses), lower RH, breezy winds with gusts in the 20-40 mph will elevate fire weather concerns. && .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 from 9 AM to 9 PM PDT Friday for Mry Bay. Small Craft Advisory until 3 AM PDT Saturday for Pigeon Pt to Pt Pinos 0-10 nm-Pigeon Pt to Pt Pinos 10-60 NM-Pt Arena to Pt Reyes 0-10 nm-Pt Arena to Pt Reyes 10-60 NM-Pt Pinos to Pt Piedras Blancas 0-10 nm-Pt Reyes to Pigeon Pt 0-10 nm. && $$ SHORT TERM...Murdock LONG TERM....Murdock AVIATION...RGass 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