Area Forecast Discussion
Issued by NWS San Francisco Bay Area, CA
Issued by NWS San Francisco Bay Area, CA
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890 FXUS66 KMTR 260406 AFDMTR Area Forecast Discussion National Weather Service San Francisco CA 906 PM PDT Wed Sep 25 2024 ...New UPDATE... .UPDATE... Issued at 858 PM PDT Wed Sep 25 2024 Forecast remains on track for temperatures tomorrow to be right around normal for this time of year, or slightly warmer, especially elevated locations farther inland. The beginning of next week may bring another round of Moderate HeatRisk for interior locations away from the marine layer influence. && .SHORT TERM... (This evening through Thursday) Issued at 104 PM PDT Wed Sep 25 2024 Quick check of current temps shows about 15-30 degrees cooler than 24 hours ago, depending on where you are. All thanks to a deep marine layer and robust onshore flow in response to a passing upper level trough in the Pacific Northwest. This pattern evolves rather quickly back to a ridge setup with effects beginning Thursday. High temps start to trend upwards Thursday as the marine layer becomes compressed and cloud cover clears sooner in the day, compared to today. Temperatures Thursday look to be about seasonal normals. Some high clouds may end up in the picture this evening for locations in the North Bay, making for a nice sunset if you`re inland or above the stratus. && .LONG TERM... (Thursday night through next Tuesday) Issued at 104 PM PDT Wed Sep 25 2024 Friday is expected to be the warmest day headed into the weekend with highs ranging 5-15 degrees above normal. There`s a short window of a weak offshore gradient that will likely set up in the morning, eroding most of the marine layer and causing temps to increase rapidly. By the afternoon, the gradient will reverse and breezy onshore flow will ensue. Therefore, there is more uncertainty than normal with the highs on Friday based on the timing of the wind reversal. A progressive Gulf of Alaska trough pattern remains through the weekend with another upper level disturbance heading into the PNW Saturday and Sunday. This will aid in flattening the ridge influence, bringing high temps back down towards normal. However, the roller coaster ride continues with a ridge influence building back in through early next week, resulting in another warming trend. Ensemble guidance shows fairly reasonable agreement in this pattern, so confidence is high that we will see above average temperatures at least through the middle of next week. && .AVIATION... (00Z TAFS) Issued at 416 PM PDT Wed Sep 25 2024 Currently VFR at all terminals with the exception of the Monterey Bay terminals of MRY and SNS. High confidence in all terminals developing MVFR ceilings overnight. A deep marine layer currently measured at 2,500 feet will aid in MVFR ceilings, VFR visibilities, and drizzle along the immediate coast. Widespread VFR will prevail by tomorrow afternoon. Vicinity of SFO...Currently VFR with westerly flow. High confidence in the terminal developing an MVFR ceiling tonight with VFR prevailing by late-morning Thursday. Winds will prevail out of the west through the TAF period with the exception of brief, light offshore flow tomorrow during the late morning/early afternoon timeframe before the sea breeze kicks in. SFO Bridge Approach...Low clouds will filter in late this evening and linger through 19Z. Monterey Bay Terminals...Currently MVFR with westerly flow at MRY and MVFR with northwesterly flow at SNS with VFR prevailing at both terminals by tomorrow afternoon. Westerly winds will veer to become northerly overnight for MRY before backing to become westerly with SNS prevailing out of the west/northwest through the TAF period. && .MARINE... (Tonight through next Monday) Issued at 416 PM PDT Wed Sep 25 2024 Light to gentle northwesterly breezes continue through the evening, strengthening to become moderate to fresh Thursday through the weekend, and causing rough seas to develop in the outer waters. && .MTR WATCHES/WARNINGS/ADVISORIES... CA...None. PZ...Small Craft Advisory from 3 AM Thursday to 9 AM PDT Friday for Pt Arena to Pt Reyes 10-60 NM. Small Craft Advisory from 3 PM Thursday to 9 AM PDT Friday for Pigeon Pt to Pt Pinos 10-60 NM. && $$ SHORT TERM...Behringer LONG TERM....Behringer AVIATION...Sarment MARINE...DialH 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