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

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165 FXUS66 KMTR 190634 AFDMTR Area Forecast Discussion National Weather Service San Francisco CA 1134 PM PDT Tue Jun 18 2024 ...New AVIATION, MARINE... .SYNOPSIS... Issued at 155 PM PDT Tue Jun 18 2024 Upper level trough will dig over California through midweek, with breezy onshore winds continuing and temperatures near seasonal averages prevailing through Thursday. The trough will remain in place, but weaken for Friday and the weekend, with warmer conditions developing once again across the inland areas. && .UPDATE... Issued at 855 PM PDT Tue Jun 18 2024 Near term weather concerns continue to be fire weather focused. Fortunately, the two more notable fires in the CWA, the Point and Coast Fires, are showing signs of much less fire activity than 24 hour. For the record, neither fire is contained and are still be attended to by fire personnel. The one notable fire, which is not in the CWA, is still impacting the region. That fire is the Sites Fire and is NE of the Bay Area. It is impacting the Bay Area with haze and smoke. Northerly transport flow ushered in smoke from the north leading to haze and reports of smoke across the North and East Bay. Any clearing of said smoke/haze has been slow going. Latest forecast guidance continues to advertise a shift to more westerly transport flow, which should help push some of the smoke/haze eastward. The latest satellite imagery does show some eastward movement of the smoke/haze. That being said, did update the forecast to include more haze across the N and E Bay this evening. While fire activity is less this evening, elevated fire weather conditions still prevail. A quick sampling of observations in the Bay Are and Central Coast still show very low humidity with readings in the upper single digits to teens. There are also some breezy conditions with gusts of 20-30 mph. Fire weather concerns will ultimately diminish gradually tonight as onshore flow increases with better humidity recovery expected. While current satellite shows no marine layer at the moment a shallow marine layer is forecast to develop along the coast and move locally inland. No other updates needed this evening. MM && .SHORT TERM... (This evening through Wednesday) Issued at 155 PM PDT Tue Jun 18 2024 Water vapor imagery continues to show the next disturbance digging south along the Central Coast this afternoon, with high clouds spreading across the region at this time. That said, the cloud cover has done little to suppress temperatures today as temperatures are currently running upwards of 8 degrees warmer than this time yesterday. Onshore gradients are starting to increase once again as well. However, not quite as strong as this time yesterday. Meanwhile, the Fort Ord Profiler is the showing an extremely compressed marine layer, about 200 feet currently. The marine layer will slowly increase this evening and tonight, with some patchy fog returning to the coastal areas during the late night and early morning hours. The upper level trough will remain over the West Coast on Wednesday, with onshore flow prevailing. Temperatures will likely cool a few degrees along the coast with the return the marine layer, while inland areas will remain seasonal. Palmer && .LONG TERM... (Wednesday night through next Monday) Issued at 155 PM PDT Tue Jun 18 2024 The upper level trough will remain over the West, but gradually start to fill Thursday through Saturday. As a result, a warming trend will develop, especially for the inland areas. At this point in time, the ensembles are hinting that Saturday will be the warmest day, with the favored hot spots reaching into the triple digits. However, there are some of the ensemble members suggesting that the subtropical ridge could finally expand into the region from the Desert Southwest, with warming conditions persisting through the first part of the work week, especially for the inland areas. Palmer && .AVIATION...
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(06Z TAFS) Issued at 1134 PM PDT Tue Jun 18 2024 MVFR/IFR CIGS are forming around the Monterey Bay and will move inland further into the night. MVFR CIGs filter into the SF Bay early Wednesday morning, filling over OAK at times. Expect winds to be light to moderate through the late morning before breezy winds arrive into the afternoon as widespread VFR returns. Winds reduce into Wednesday evening as MVFR and IFR CIGs begin to affect the Monterey Bay and SF Bay terminals. Vicinity of SFO...VFR lasts through Wednesday evening. Winds Stay moderate through the morning with another round of breezy winds start in the afternoon with peak gusts around 26 kts. These winds reduce into the evening as MVFR CIGs fill over the terminal SFO Bridge Approach...Similar to SFO. Monterey Bay Terminals...MVFR/IFR CIGs fill over the terminals into the late night with light to moderate winds. CIGS erode into the mid to late morning as moderate to breezy winds arrive. Winds at the terminals reduce into the evening as IFR CIGs move inland.
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&& .MARINE...
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(Tonight through next Monday) Issued at 1134 PM PDT Tue Jun 18 2024 Gusty northwest winds will ease somewhat overnight but remain breezy through late Wednesday morning, and persist through Thursday morning. Northwest winds increase again late Thursday evening across northern waters, remaining gusty through the weekend. Significant wave heights have returned to around 6-8 feet, but will build back up to 10-12 feet towards the end of the the weekend as larger northwesterly swell returns.
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&& .MTR WATCHES/WARNINGS/ADVISORIES...
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CA...None. PZ...Small Craft Advisory until 9 PM PDT Wednesday for Pt Arena to Pt Reyes 0-10 nm-Pt Pinos to Pt Piedras Blancas 0-10 nm. Small Craft Advisory until 9 AM PDT Wednesday for Pigeon Pt to Pt Pinos 10-60 NM-Pt Arena to Pt Reyes 10-60 NM-Pt Reyes to Pigeon Pt 0-10 nm. Small Craft Advisory from 9 PM Wednesday to 9 AM PDT Thursday for Pt Arena to Pt Reyes 10-60 NM.
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&& $$ SHORT TERM...Palmer LONG TERM....Palmer AVIATION...Murdock MARINE...JM 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