FXUS66 KMTR 051749 AFDMTR Area Forecast Discussion National Weather Service San Francisco CA 1049 AM PDT Thu Jun 5 2025 ...New AVIATION, MARINE... .SYNOPSIS... Issued at 252 AM PDT Thu Jun 5 2025 Fair weather continues over the next several days with cloudy mornings and clear afternoons. Temperatures around seasonal normals with a slight warming trend over the weekend. && .SHORT TERM... Issued at 252 AM PDT Thu Jun 5 2025 (Today and tonight) Key Messages -Marine layer persists Overnight satellite fog product once again reveals a solid marine layer blanketing the coast and inland valleys. A comparison to 24 hours ago also shows better stratus coverage this morning as well. This makes sense given the deeper marine layer with a depth of close to 1700-2000 feet per profilers. The deeper marine layer is likely due to passing upper level shortwave with a slight dip in 500mb heights. Otherwise, overall sensible weather for today and tonight will be similar to Wednesday. Morning marine layer, which includes low clouds, fog, drizzle, will gradually roll back to the coast. Just like Wednesday, coastal areas will not completely clear given lingering onshore flow. Given the deep push clearing of inland areas will be a slightly later than yesterday. Regardless still expecting inland sunshine. Temperatures today will be seasonably cool with the coast upper 50s and 60s and interior 70s to near 90. Onshore flow is forecast to peak around 4mb, which will result in breezy to gusty winds again this afternoon/evening for the coast and any inland valley/gap/pass. For tonight, marine layer will rush back inland with low clouds, fog, and drizzle && .LONG TERM... Issued at 333 AM PDT Thu Jun 5 2025 (Friday through Wednesday) Key Messages -Gradual warming trend over the weekend into Tuesday Heading into Friday we'll see a shift in the upper level longwave pattern. A very amplified and wavy jet rides the ridge into the PacNW before taking a 180 and digging SW into California. The digging jet will help facilitate the development of a cut-low over the Bay Area Friday. This low will gradually retrograde or meander off the CA coast heading into the weekend. As the low meanders ridging develops inland. While ridging will bring a warmer weather Friday through Tuesday the nearby upper low will keep some variation of a marine layer intact. As such, we'll see a larger temp spread from the coast to inland areas. Warmest inland areas will reach the 90s and take a run at 100 degrees Monday and Tuesday. A cooling trend looks to develop by the middle of next week with broader troughing developing aloft. One fly in the ointment will be the pesky upper low developing over the region with a slight easterly flow aloft. Not all models show it, but a few of them do hint that the upper low will pull some moisture in from the east. Additionally, a few of the convectively hot models (NAM) even generate some MUCAPE over the N Bay this weekend. Not mentioning any convection at this time and not even a non-zero chance, but wanted to at least mention it. && .AVIATION... (18Z TAFS) Issued at 1049 AM PDT Thu Jun 5 2025 MVFR ceilings linger over the North Bay and Monterey Bay region at this hour but are anticipated to become VFR by late morning or early afternoon. The exception will be at HAF where MVFR ceilings will persist through much of the day. Onshore winds increase this afternoon and ease after sunset. There is high confidence for MVFR/IFR ceilings to return to the Monterey Bay terminals late this evening and the Bay Area terminals early Friday morning. Vicinity of SFO...VFR conditions have returned to the Bay Area terminals as of this writing with onshore winds expected to increase through early afternoon. There is high confidence for ceilings to return by early Friday morning, generally in the MVFR range. Ceilings will return to VFR by Friday afternoon with increasing onshore flow. SFO Bridge Approach...Similar to SFO. Monterey Bay Terminals...MVFR ceilings linger at MRY while SNS has returned to VFR. VFR conditions are expected this afternoon with an increase in onshore winds. High confidence for an early return to MVFR ceilings early this evening, lowering to IFR by early Friday morning. && .MARINE... (Today through Tuesday) Issued at 1049 AM PDT Thu Jun 5 2025 A moderate to strong northerly breeze is diminishing in the outer waters while strong southerly winds persists through the day along the coast and in the northern San Francisco Bay. The pressure gradient will relax over the next 30 hours, causing winds to diminish and allowing seas to subside. Mostly favorable conditions will persist through the weekend with a long period SW swell arriving early next week. && .MTR WATCHES/WARNINGS/ADVISORIES... CA...None. PZ...Small Craft Advisory until 9 PM PDT this evening for Pt Reyes to Pigeon Pt 0-10 nm-SF Bay N of Bay Bridge. Small Craft Advisory until 3 PM PDT this afternoon for Pt Arena to Pt Reyes 10-60 NM. && $$ SHORT TERM...MM LONG TERM....MM AVIATION...RGass MARINE...Flynn 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