Area Forecast Discussion
Issued by NWS San Francisco Bay Area, CA

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143 FXUS66 KMTR 122051 AFDMTR Area Forecast Discussion National Weather Service San Francisco CA 151 PM PDT Wed Jun 12 2024 ...New SYNOPSIS, SHORT TERM, LONG TERM... .SYNOPSIS...
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Issued at 1234 PM PDT Wed Jun 12 2024 Quiet through the rest of the week. Near normal temps by the weekend. Increasing confidence for high wind potential and increased fire danger Sunday into early next week.
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&& .SHORT TERM...
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(This evening through Thursday) Issued at 1234 PM PDT Wed Jun 12 2024 Noticeably cooler temps today across the area as the upper level ridge moves out and the marine layer deepens in response to a weak mid level shortwave trough. Additionally, more robust marine stratus associated with moisture from a weak disturbance off the coast of southern CA will continue to linger for areas from around Santa Cruz to the Big Sur coast. A few degrees warmer for Thursday as the shortwave kicks out. Overall not much in the way of impactful changes in the short term. Pleasant day ahead on Thursday with little in the way of heat risk.
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&& .LONG TERM...
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(Thursday night through next Tuesday) Issued at 1234 PM PDT Wed Jun 12 2024 Heading into the weekend will be relatively quiet as temps cool a bit again down to around seasonal normals. The real story will be later in the weekend and into early next week. A deep upper low currently up in the Gulf of Alaska becomes dislodged and moves into the Pacific Northwest, kicking off another deep disturbance sliding into the West Coast/Great Basin. Well advertised by ensemble cluster analysis, there is high confidence in this pattern change taking place Sunday into Tuesday. Placement of the upper level trough axis is key when determining where the strongest winds will be and their direction. There is higher confidence that the strongest winds will remain over the waters and near coastal areas, including more inland coastal gaps such as the Petaluma Gap, San Bruno Gap, and other NW-SE oriented valleys. While we aren`t expecting any widespread offshore winds as of this forecast, the positioning of the trough will ultimately be the deciding factor, so stay tuned to future updates as confidence gradually increases. With grasses and fine fuels drying out rapidly, it looks like the Sunday-Monday timeframe is one to watch when it comes to elevated fire danger, particularly in the North Bay where fine fuels are drier than elsewhere around the Bay Area and Central Coast. For now, moisture recovery looks decent going into the weekend as winds should remain onshore, but we are keeping a close eye on the positioning of the trough and will update messaging accordingly.
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&& .AVIATION... (18Z TAFS) Issued at 1028 AM PDT Wed Jun 12 2024 Satellite shows the stratus continues to linger over Monterey Bay. With the slight eddy rotation, expect ceiling to linger longer into early afternoon. Otherwise, VFR for the remainder of the terminals. MVFR-IFR conditions will return for Monterey Bay late afternoon and MVFR conditions will build for North Bay late tonight, as the other remaining terminals will remain VFR. With the building marine layer, expect some scattered low clouds to reach some of the remaining terminals, but moderate confidence that conditions will remain VFR. Winds will become breezy and gusty this afternoon into the evening, before becoming light to moderate overnight. Vicinity of SFO...VFR continue with N/NW moderate winds. Onshore winds will build to breezy and gusty this afternoon up to 25 knots before returning to moderate by the night. Models hint at MVFR tonight but had low confidence to include in TAFs at this moment but included a SCT group to indicate low clouds will surround the airport. SFO Bridge Approach...Similar to SFO. Monterey Bay Terminals...IFR conditions continue but ceilings are slowly lifting. Models show ceilings may not lift to VFR through the TAF period, but confidence is low so expect brief VFR near 20-21Z. MVFR will have a early return near 23Z. SW winds will continue through the TAF period with increasing speeds near the afternoon with possible gusty up to 20 knots. The SW direction winds will make it harder for ceilings to clear and will allow for a early return of MVFR-IFR conditions this afternoon into Thursday morning. && .MARINE... (Today through Monday) Issued at 1028 AM PDT Wed Jun 12 2024 Northwesterly winds continue over the northern waters through the end of the week with gale force gusts possible over the northern waters through the day today, but diminish into the late night tonight. Widespread strong northwesterly winds with gale force gusts will build in by the weekend and continue into next week. Significant wave heights diminish later today to become 10-12 feet over the outer waters, and last through the remainder of the week. && .MTR WATCHES/WARNINGS/ADVISORIES... CA...None. PZ...Small Craft Advisory until 3 AM PDT Thursday for Pt Arena to Pt Reyes 0-10 nm. Gale Warning until 3 AM PDT Thursday for Pt Arena to Pt Reyes 10- 60 NM. Small Craft Advisory until 3 PM PDT this afternoon for Pigeon Pt to Pt Pinos 10-60 NM. && $$ SHORT TERM...Behringer LONG TERM....Behringer AVIATION...SO MARINE...SO Visit us at www.weather.gov/sanfrancisco Follow us on Facebook, Twitter, and YouTube at: www.facebook.com/nwsbayarea www.twitter.com/nwsbayarea www.youtube.com/nwsbayarea