Area Forecast Discussion
Issued by NWS Columbia, SC

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000 FXUS62 KCAE 211937 AFDCAE Area Forecast Discussion National Weather Service Columbia SC 237 PM EST Tue Jan 21 2020 .SYNOPSIS... High pressure will ridge into the forecast area from the north through Thursday. There will be increased moisture ahead of a frontal system Thursday night. The front will be in the region Friday and move off the coast Friday night. High pressure will dominate Saturday and Sunday. && .NEAR TERM /THROUGH TONIGHT/... Cool, dry air will continue to filter into the region this afternoon. Highs will only be in the 40s. North or NNE winds will persist through the period with gusts this afternoon around 20 mph. Expect clear skies overnight, but winds will stay up preventing ideal radiational cooling conditions. Some of the stronger winds aloft may be able to mix down over the relatively warm lake waters. Winds may still gust to around 20 mph over the lakes but are not anticipated to exceed Lake Wind Advisory Criteria. Lows will be in the 20s again. && .SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/... Wednesday and Wednesday night...Surface ridging will extend into the area from the north through Wednesday night. Upper ridging over the region will shift off the coast late Wednesday night. It will remain dry. Followed a model blend for the temperature forecast. It again will be cold Wednesday night with lows mainly in the upper 20s. The MAV and MET MOS support wind mainly northeast near 10 mph Wednesday and light Wednesday night. Thursday through Friday night...The models show surface high pressure continuing to ridge into the forecast area from the north or northeast Thursday and Thursday night. Increased isentropic lift is depicted over this wedge ridge mainly late Thursday night. There may also be increased moisture ahead of a mid-level shortwave trough late Thursday night. A model blend supports pops increasing to likely in the west part toward morning. Convergence ahead of the front and isentropic lift support high pops through Friday although the moisture may become more shallow behind a mid-level shortwave for Thursday afternoon. A model blend supports categorical or likely pops during the day. The front is forecast to shift east of the area Friday night. Rain should end from west to east behind the front Friday night. A model blend has rain totals 0.4 to 0.7 of an inch. The greater amounts may be in the north part closer to greater upper lift. The wedge pattern indicates a concern for freezing rain at the start during the early morning hours Friday, but the NAM, GFS, and ECMWF, plus nearly all ensemble members have been consistent keeping temperatures above freezing. We maintained the all-liquid forecast. Leaned toward the lower temperature guidance Thursday because of a cold start and increased cloudiness. Followed the guidance consensus for the temperature forecast Thursday night through Friday night. && .LONG TERM /SATURDAY THROUGH TUESDAY/... The GFS and ECMWF show dry surface high pressure and a low amplitude upper pattern during the period. Significant moisture ahead of upper systems are depicted remaining north and south of the forecast area. The GFS and ECMWF MOS indicate less than 20 percent pops and near-normal temperatures. && .AVIATION /20Z TUESDAY THROUGH SUNDAY/... VFR conditions will continue through the TAF period. Expect N to NNE winds through tonight with gusts near 20 kt during the afternoon. Winds will stay up overnight from 5 to 10 kts but the stronger gusts will subside. A 30 to 40 kt nocturnal jet will develop over the TAF sites but the stronger winds should be above 2000 ft AGL and confidence is not high enough to include LLWS in the TAFs at the moment. No fog expected due to the dry air mass in place. Dry weather will continue Wednesday with NE winds from 5 to 10 kts. EXTENDED AVIATION OUTLOOK...No significant impacts to aviation expected through Thursday. Showers and associated restrictions Thursday night and Friday. && .CAE WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. && $$

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