Area Forecast Discussion
Issued by NWS San Francisco Bay Area, CA
Issued by NWS San Francisco Bay Area, CA
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674 FXUS66 KMTR 070007 AAB AFDMTR Area Forecast Discussion...UPDATED National Weather Service San Francisco CA 507 PM PDT Thu Jun 6 2024 ...New AVIATION... .SYNOPSIS... Issued at 1215 PM PDT Thu Jun 6 2024 Slightly cooler temperatures today with a further cool down into the weekend. Another warming trend on the way for early next week. && .SHORT TERM... (This evening through Friday) Issued at 1215 PM PDT Thu Jun 6 2024 Mid day temperatures running anywhere from 3 to 15 degrees cooler than yesterday depending on location. Thanks to the upper level ridge migrating eastward and a transient shortwave trough moving into the West Coast. This is evident in not only the marked decrease in temperatures, but via vertical profilers showing a deepening of the marine layer as large scale subsidence diminishes. Overnight lows tonight are expected to be about 1-5 degrees cooler than last night, and highs Friday look to be about 3-6 degrees cooler than today...unless you`re along the coast, in which the only noticeable difference day-to-day will be increased overnight cloud cover and potentially morning drizzle into the weekend. && .LONG TERM... (Friday night through next Wednesday) Issued at 1215 PM PDT Thu Jun 6 2024 Things stay pretty quiet through the weekend. Onshore flow and slightly above average temperatures prevail, and guidance hints at a deeper upper level trough associated with the deep low in the Gulf of Alaska sitting offshore of the West Coast into the start of next week. As previously mentioned, this will likely just result in increased cloud cover along the coast and AM drizzle for coastal and high elevation locations through Sunday. By Monday, the trough begins to break down and become replaced by another ridge pattern, which leads to our next warm up. At the moment, ensemble guidance is leading us to believe that it will not be quite as warm as the last couple of days, but it is a period we`re watching for potential highlights with Tuesday looking like the peak based on this forecast issuance. && .AVIATION... (00Z TAFS) Issued at 438 PM PDT Thu Jun 6 2024 While VFR is forecast to continue through sunset, flight conditions will deteriorate quickly at Monterey Bay Terminals by 03Z (IFR cigs/visibility). At Bay area terminals MVFR is forecast to arrive around 06Z, with MVFR/IFR visibility closer to 10Z at the North Bay airports. LVK and SJC have around a 10% chance of MVFR, but the current TAF for these aerodromes is VFR. Largely onshore flow is forecast through the TAF period with winds subsiding some after 04 UTC. Confidence is medium in flight category forecasts and medium to high in the wind forecasts. Vicinity of SFO...WNW winds will slowly subside through 04 UTC, though a few gusts to near 25 knots cannot be ruled out. MVFR stratus is forecast to invade from the west/through the San Bruno Gap around sunrise tomorrow, with intermittent BR bringing visibility down to IFR during the AM push. Confidence is high enough to advertise a brief period of VFR in the afternoon, before MVFR stratus returns. If the marine layer is deeper than currently anticipated, MVFR may prevail through the entire TAF period. The TAF for tomorrow afternoon is a bit more optimistic with VFR forecast. MVFR is advertised to return in the extended portion of the TAF, however, additional forecasts will need to address any IFR ceiling potential. SFO Bridge Approach...Similar to SFO, though the onset/cessation of MVFR stratus may differ by up to 1 hour. Monterey Bay Terminals...Poor flying conditions are forecast within the next couple of hours with MVFR stratus yielding to IFR ceilings and visibility. Confidence is medium to high on the ceiling and visibility forecast. LIFR cigs are forecast to set in just prior to midnight and prevail through the pre-dawn hours on Friday. Cigs are forecast to lift into the MVFR category late morning/early afternoon on Friday, though confidence in the exact timing is medium to low. In fact, if the marine layer is a bit deeper, MVFR could prevail until late in the TAF period. For now, I`ll advertise a more optimistic TAF and we`ll monitor forecast trends and adjust if needed. && .MARINE... (Tonight through next Tuesday) Issued at 339 PM PDT Thu Jun 6 2024 Northerly winds of 10 to 20 knots with gusts in the 25 to 30 knot range are forecast to subside through this evening and into Friday. Westerly long period...near 15 seconds...swell will persist and result in hazardous boating and beach conditions through the evening hours. Conditions are forecast to improve through Friday, however, seas are forecast to rebuild Saturday and into Sunday and additional marine hazards may be necessary. && .BEACHES... Issued at 339 PM PDT Thu Jun 6 2024 Westerly to northwesterly long period swell will continue to impact area beaches. Wave periods near 15 seconds and heights near 10 feet are still forecast. The sneaker wave potential will persist into this evening. The threat for people and animals being pulled in the water from rocks, jetties, and beaches will also continue. Inexperienced swimmers should stay out of the water. Observe the ocean for 20 minutes before relaxing on the beach. Know where lifeguards are, obey their instructions, and never turn your back on the ocean! && .MTR WATCHES/WARNINGS/ADVISORIES... CA...Beach Hazards Statement until midnight PDT tonight for CAZ006- 505-509-530. Heat Advisory until midnight PDT tonight for CAZ503-504-506-510- 512>516-518. PZ...Small Craft Advisory until 3 AM PDT Friday for Pt Arena to Pt Reyes 0-10 nm. Small Craft Advisory until 9 PM PDT this evening for Pigeon Pt to Pt Pinos 10-60 NM-Pt Reyes to Pigeon Pt 0-10 nm. Small Craft Advisory until 3 PM PDT Friday for Pt Arena to Pt Reyes 10-60 NM. && $$ SHORT TERM...Behringer LONG TERM....Behringer AVIATION...Bain MARINE...Bain 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