FXUS66 KMTR 030826 AFDMTR Area Forecast Discussion National Weather Service San Francisco CA 126 AM PDT Thu Apr 3 2025 ...New SYNOPSIS, SHORT TERM, LONG TERM... .SYNOPSIS... Issued at 123 AM PDT Thu Apr 3 2025 Gradual warming and drying trend through Saturday with a slight chance for rain Sunday. Warming and drying trend resumes Monday. && .SHORT TERM... (Today and tonight) Issued at 123 AM PDT Thu Apr 3 2025 A Frost Advisory is in effect through 9 AM for the North Bay Interior Valleys and the Interior Central Coast. This cold airmass will also be responsible for putting three climate sites daily minimum temperatures in jeopardy this morning: San Rafael (SARC1) forecast is 42 degrees with a previous record of 39 degrees in 2010, San Francisco Downtown (SFOC1) forecast is 44 degrees with a previous record of 41 degrees in 2001, and Oakland Museum (OAMC1) forecast is 44 degrees with a previous record of 43 degrees in 2003. Light winds and remnant moisture will allow for fog development through the morning hours, so ensure to use your low-beam headlights, drive slowly, and keep your distance from other vehicles. The warming and drying trend continues today, but temperatures will still remain several degrees below average. Cold conditions will return overnight largely remaining confined to the higher terrain; nonetheless, ensure the protection of people, pets, plants, and pipes. && .LONG TERM... (Friday through Wednesday) Issued at 123 AM PDT Thu Apr 3 2025 A high-amplitude longwave ridge of high pressure will build into the West from the Eastern Pacific Ocean through Saturday. At the surface, this will translate to the return of above seasonal normal temperatures and minor HeatRisk. As a reminder, this level of heat affects primarily those individuals extremely sensitive to heat, especially when outdoors without effective cooling and/or adequate hydration. An upper-level low will shift the ridge eastward (effectively flattening the pattern to zonal flow) Sunday into Monday with a cold front slated to bring precipitation of up to 0.25" to the North Bay. The ridge rebuilds and begins to retrograde Tuesday with temperatures climbing to as much as 15 degrees above average by Wednesday. && .AVIATION... (06Z TAFS) Issued at 1039 PM PDT Wed Apr 2 2025 Patchy MVFR CIGs along the coastline and Monterey Bay region with highest confidence in MVFR CIGs continuing to impact HAF and MRY. NBM is best representing the current satellite setup which shows cloud cover across the South Bay and interior Monterey County diminishing, decreasing confidence that CIGs will reach SJC or SNS. Some potential for fog during the early morning hours at STS and APC but confidence is low with local WRF guidance suggesting conditions will be on the drier end. Gusty onshore flow continues at OAK, SFO, and HAF but has diminished from earlier this afternoon. Winds continue to diminish overnight before widespread moderate onshore flow returns during the day tomorrow. Vicinity of SFO...VFR. Patchy MVFR CIGs are possible overnight but confidence is low. HREF and NBM guidance keep CIGs more directly along the coastline which should keep CIGs away from SFO. Gusty onshore flow will continue to diminish overnight before moderate west to northwest winds return during the day tomorrow. SFO Bridge Approach...Similar to SFO. Monterey Bay Terminals...Borderline VFR/MVFR conditions at MRY overnight, VFR at SNS. Low clouds continue in the vicinity of MRY with BKN CIGs hovering on the BKN030-035 border. Current thinking is CIGs will hover closer to BKN030 with temporary decreases to between BKN025-030 possible. CIGs look to remain slightly higher at SNS where VFR conditions persist through the TAF period. Onshore flow will continue to diminish overnight with moderate west to northwest winds expected during the day tomorrow. && .MARINE... (Tonight through next Tuesday) Issued at 1039 PM PDT Wed Apr 2 2025 A strong north to northwest breeze and rough seas continue over the coastal waters through early Friday morning. Winds will diminish heading into the weekend with a moderate to fresh breeze persisting into next week. Wave heights will continue to abate tonight into the weekend but are expected to build again Sunday into next week as the next round of moderate long period swell reaches the coastal waters. && .MTR WATCHES/WARNINGS/ADVISORIES... CA...Frost Advisory until 9 AM PDT this morning for CAZ506-516>518. PZ...Small Craft Advisory until 3 AM PDT early this morning for Pigeon Pt to Pt Pinos 0-10 nm-Pt Arena to Pt Reyes 0-10 nm- Pt Reyes to Pigeon Pt 0-10 nm. Small Craft Advisory until 3 AM PDT Friday for Pigeon Pt to Pt Pinos 10-60 NM-Pt Arena to Pt Reyes 10-60 NM-Pt Pinos to Pt Piedras Blancas 0-10 nm. && $$ SHORT TERM...Sarment LONG TERM....Sarment AVIATION...Kennedy MARINE...Kennedy 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