Area Forecast Discussion
Issued by NWS San Francisco Bay Area, CA
Issued by NWS San Francisco Bay Area, CA
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931 FXUS66 KMTR 130949 AFDMTR Area Forecast Discussion National Weather Service San Francisco CA 249 AM PDT Thu Jun 13 2024 ...New SYNOPSIS, SHORT TERM, MARINE... .SYNOPSIS... Issued at 247 AM PDT Thu Jun 13 2024 Quiet through the rest of the week with slight warm up on Friday across the interior. Near normal temperatures by the weekend. Increasing confidence for high wind potential and increased fire danger Sunday into early next week. && .SHORT TERM... (Today through Friday) Issued at 247 AM PDT Thu Jun 13 2024 Temperatures this afternoon will be similar to those yesterday as zonal flow conditions north of the region while an upper level low remains parked off of southern California. Temperatures this afternoon will range from the upper 50`s to 60`s near the coast and bayshore, 70`s to near 80 degrees just inland and into the East Bay, Santa Clara Valley, and southern Salinas Valley. The regions farthest interior will reach into the upper 80`s to low 90`s. Tonight, expecting less widespread stratus to penetrate inland as the marine layer begins to compress. Overnight low temperatures are forecast to be in the upper 40`s across the North Bay and San Francisco Peninsula with low/mid 50`s elsewhere. Friday will be slightly warmer in response to increased sunshine, northerly winds, and weak ridging aloft. Coastal/bayshore areas will remain cool but the interior will see more upper 80`s to low 90`s. && .LONG TERM... (Friday night through Wednesday) Issued at 247 AM PDT Thu Jun 13 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. && .AVIATION... (06Z TAFS) Issued at 1059 PM PDT Wed Jun 12 2024 VFR through the TAF period for SF Bay terminals, though North Bay and Monterey Bay terminals are expected to develop or maintain IFR/LIFR CIGs through the majority of the overnight period tonight. For North Bay terminals, IFR conditions are expected to improve as CIGs lift beyond sunrise, with clearing to VFR shortly after. Meanwhile, Monterey Bay terminals are not expected to clear to VFR during the day on Thursday. Winds light overnight tonight, but increase to become breezy into the afternoon of Thursday. Vicinity of SFO...VFR through the TAF period, with moderate confidence. Stratus may hover near the terminal, but not expecting CIGs to develop. Winds generally light overnight but increase out of the SW in the morning to become breezy, eventually turning to flow out of the NW in the late afternoon. Winds then decrease into the late night of Thursday. SFO Bridge Approach...Similar to SFO. Monterey Bay Terminals...Currently IFR as stratus continues to feed inland off of the coast. CIGs are expected to lower throughout the night, eventually leading to the development of LIFR conditions. Heavy mist is likely to develop as CIGs lower as well, lowering visibilities significantly in the overnight tonight. Towards sunrise, CIGs will begin to lift, eventually becoming MFR towards the late morning. Not expecting clearing for KMRY or KSNS terminals Thursday. Winds W/SW and breezy. A return to IFR conditions expected in the late night of Thursday. && .MARINE... (Today through Tuesday) Issued at 247 AM PDT Thu Jun 13 2024 Fresh northwesterly winds continue over the northern waters through the end of the week. Towards the weekend, northwesterly winds strengthen to become strong and gusting to gale-force over much of the waters. Significant wave heights up to around 12 to 15 feet in the outer waters continue into the weekend. && .MTR WATCHES/WARNINGS/ADVISORIES... CA...None. PZ...Small Craft Advisory until 3 AM PDT early this morning for Pt Arena to Pt Reyes 0-10 nm. Small Craft Advisory from 3 PM this afternoon to 9 AM PDT Friday for Pigeon Pt to Pt Pinos 10-60 NM-Pt Arena to Pt Reyes 0- 10 nm. Gale Warning until 3 AM PDT early this morning for Pt Arena to Pt Reyes 10-60 NM. Small Craft Advisory until 9 AM PDT Friday for Pt Arena to Pt Reyes 10-60 NM. && $$ SHORT TERM...RGass LONG TERM....Behringer AVIATION...AC MARINE...AC 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