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

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000 FXUS66 KMTR 221813 AFDMTR Area Forecast Discussion National Weather Service San Francisco Bay Area 1013 AM PST Wed Feb 22 2017 .SYNOPSIS...A few lingering showers will be possible today into early Thursday morning, mainly offshore and near the coast. Otherwise, drier and much cooler conditions are forecast through late week with chilly overnight/morning temperatures. Unsettled weather conditions return by the weekend with the potential for widespread rain and gusty winds. && .DISCUSSION...as of 9:51 AM PST Wednesday...radar scans continue to pick up a few showers just off the San Mateo coast. Expect these to continue this morning, but mainly along and near to the coast. Mostly dry conditions are expected elsewhere. Cooler daytime temperatures are expected today with our cooler and drier airmass, with high temperatures only in the low to mid 50s in the lower elevations and 40s more common in the hills. Similar conditions are anticipated through Thursday along with an isolated shower or two late tonight into early Thursday morning as a weak weather system drops southward along the coast. The best chance for any showers will be over the coastal waters and along the coastal ranges while inland areas will likely remain dry through Friday. The cooler and drier air mass settling into the area along with lighter winds will allow for some chilly overnight/morning temperatures, especially in inland valleys. Low temperatures will likely fall into the 30s, even upper 30s to near 40 near the coast. Inland, wind sheltered areas can expect a period of sub freezing temperatures both late tonight/Thursday morning and again Thursday night/Friday morning. With this too, patchy frost will be possible in the coldest, inland valley locations. Forecast models continue to show another storm system slated to affect the district this weekend. Latest model runs, however, are trending to a less-wet northwest flow pattern and cold upper low moving across the area, without the connection to the moist, subtropical tap. The 12Z run of the GFS is now more in line with last night`s ECMWF run that indicated this scenario. The district will likely see cold showers moving across, but latest rainfall estimates are not much more than a half inch. Will continue to monitor the forecast runs and see how this progresses. Folks are urged to stay up-to-date with the latest forecast as we fine tune details for the upcoming weekend. && .AVIATION...
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As of 10:15 AM PST Wednesday...For 18z Tafs. Widespread VFR today. Breezy to occasionally gust onshore winds through midday and into the evening. Unstable air mass will contribute to cumulus development between 3000-5000 ft today with some VCSH or brief -SHRA possible. Can not rule out an isolated thunderstorm over the North Bay. Winds weaken tonight with patchy dense fog posbl for North Bay vallies overnight. Vicinity of KSFO...Mainly VFR. Breezy onshore winds, gusty by afternoon hours, ranging 10-20 kt with gusts up to 25 kt. Winds decrease late tonight or early Thursday morning. SFO Bridge Approach...Similar to SFO. Monterey Bay Terminals...Mainly VFR today. Moderate and gusty onshore winds by early afternoon.
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&& .MARINE...
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as of 10:07 AM PST Wednesday...Increasing northwesterly winds today and tomorrow. Winds turn light and variable on friday. Winds shift to become southerly and increase later Saturday into Sunday. The northwest swell will gradually taper off in strength through the coming days. Hazardous conditions from squared seas will exist in portions of the coastal waters through the coming days as well.
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&& .MTR WATCHES/WARNINGS/ADVISORIES...
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.Tday...SCA...Pigeon Pt to Pt Pinos 0-10 nm from 2 PM SCA...Pigeon Pt to Pt Piedras Blancas 10-60 nm from 2 PM SCA...Pt Pinos to Pt Piedras Blancas 0-10 nm SCA...Rough Bar Advisory for SF Bar SCA...Mry Bay from 2 PM
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&& $$ PUBLIC FORECAST: Sims AVIATION: DRP MARINE: DRP 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

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