397 FXUS62 KRAH 162047 CCA AFDRAH AREA FORECAST DISCUSSION National Weather Service Raleigh NC 345 PM EST Tue Feb 16 2021 .SYNOPSIS... Cold high pressure will build across the region from the north tonight and Wednesday, ahead of another low pressure system that will affect the region late Wednesday night and Thursday. && .NEAR TERM /TONIGHT THROUGH WEDNESDAY/... As of 157 PM Tuesday... High pressure currently centered over the Midwest will build east overnight and eventually southward down the Mid Atlantic region on Wednesday. Meanwhile, short wave ridging aloft will persist over the Carolinas during this period. Given the drying that has occurred behind yesterday's system, coupled with the aforementioned ridging, look for dry weather during the near term period. The current well-mixed BL that is resulting in wind gusts around 20kt attm will relax after sunset this evening, although winds won't go completely calm given the CAA and sfc ridging building to our north and into our area overnight. While dry weather is in the forecast for Wednesday, after a mostly sunny start to the day, clouds will be on the increase thanks to the continuation of the ridge building down into our area from the north, it's NE low level flow, all the while establishing CAD across the Piedmont. The resulting low level moist upglide will turn the sky rather cloudy by mid to late day with cigs around 2-3kt ft. With CAA the main factor, lows tonight will range from the mid 20s NW to around 30 SE. Daytime highs Wednesday will be cooler than today, thanks again to CAA but also increasing clouds. Highs from the lower 40s NW to upper 40s SE. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/... As of 330 PM Tuesday... Significant ice from freezing rain expected Wednesday night into Thursday... A 1035 mb surface high across NY state Wednesday night will maintain cold air damming across the region ahead of the next round of precipitation. A warm front will move northeast along the GA/SC/NC coast Wednesday night, then a surface low will move northeast from the northern Gulf of Mexico across the Southeast Thursday and offshore into the Mid-Atlantic Thursday night. This will create multiple waves of precipitation across the region Wednesday night through Friday morning. Cold air will be in place at the surface, with a warm nose aloft. This will create the possibility of freezing rain for portions of the northern Piedmont and northern Coastal Plain, with rain elsewhere. Significant icing to one-quarter of an inch is possible mainly north of I-85, with lesser amounts expected for the lower areas of the northern Piedmont. All areas should have rain as the main precipitation type by Thursday evening as temperatures increase to above freezing. A Winter Storm Watch remains in effect and a Winter Weather Advisory will likely be needed for areas elsewhere that icing is forecast. MUCAPE of 300-600 J/kg will create the possibility of isolated thunderstorms, mainly for the southeastern half of central NC. SPC has a sliver of Sampson county in a Marginal Risk for strong to severe storms Wednesday night through Thursday morning. Showers will come to an end from west to east Friday late morning/early afternoon as a shortwave trough pushes across the region. Precipitation totals through the period will range from 1.50 to just over 2.00 inches. Lows Thursday morning will dip into the upper 20s north to upper 30s south, then temperatures will only increase to the mid 30s for northern areas by the evening with highs in the low 50s across the extreme southeast. Lows Friday morning will range from the low 30s north to the mid 40s southeast, then temps increase to the mid 40s north and low 50s south by Friday afternoon. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... As of 330 PM Tuesday... In the upper-levels, zonal flow to start the weekend will become southwesterly by the end of the weekend as a weak ridge builds across the region. A trough will then swing across the region on Monday, with west to northwesterly flow following behind on Tuesday. At the surface, high pressure will build from the TN Valley Friday night into the Mid-Atlantic Sunday, and offshore Sunday night. A low will then move from the Great Lakes Region into the Northeast on Monday and Monday night, with a cold front moving across NC on Monday. High pressure then builds from the Rockies into the northern Gulf of Mexico on Tuesday. This pattern will bring welcomed dry weather to the region for the weekend as high pressure build close to the area. Cold air advection will help lows Friday night dip into the low 20s north to upper 20s south. Saturday will be cold with highs in the mid 30s north to low 40s south, but at least it should be mostly sunny. Similar lows are expected Saturday night, then winds shifting northeasterly will help temperatures rise into the 40s everywhere by the afternoon. Lows Sunday night will dip into the mid 30s, however temperatures are expected to rise well above freezing before the next round of precipitation begins with the cold front on Monday. Highs will range from the upper 40s NW to the upper 50s SE on Monday. Rain will exit the region by late Monday night, with dry weather Tuesday and highs in the mid to upper 50s. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... As of 1256 PM Tuesday... Through 18Z Wednesday: ATTM, the IFR conditions in the Triad have finally lifted to MVFR, with VFR elsewhere east of the KGSO. for the rest of daylight hours today, BL heating may result in a thin patches of MVFR stratocu pretty much anywhere across central NC. Other other noteworthy item will be gusty west winds the rest of today, with sustained speeds 10-15kt with 25+kt gusts. After sunset, look for the winds to diminish, with skies becoming partially clear. After 10Z tomorrow, the low level flow is expected to become NE with high pressure building to our north, this will set up a CAD pattern, with low clouds developing during the late morning across much of central NC, with MVFR cigs, and potentially IFR cigs later in the day across the Triad. After 18Z Wednesday: IFR or worse conditions will develop late Wed through Thu night associated with the CAD and precip event moving across the region. The precipitation is likely to be in the form of freezing rain at INT/GSO once again for most of Thu, with a shorter- lived period of FZRA possible at RDU Thu morning. && .RAH WATCHES/WARNINGS/ADVISORIES... Winter Storm Watch from late Wednesday night through Thursday evening for NCZ007>010-021>025. && $$ SYNOPSIS...np NEAR TERM...np SHORT TERM...JJT LONG TERM...JJT AVIATION...np