Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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153 FXUS62 KRAH 120755 AFDRAH Area Forecast Discussion National Weather Service Raleigh NC 300 AM EST Tue Dec 12 2017 .SYNOPSIS... A pair of dry cold fronts will cross central North Carolina today. Cold high pressure will build in tonight through Wednesday. A fast moving upper level disturbance will move through the region Wednesday night. && .NEAR TERM /TONIGHT/... As of 925 PM Monday... Clear skies this evening will give way to increasing cloud cover overnight as a potent s/w disturbance and associated cold front approach from the west. In addition to the increasing cloud cover, expect we`ll see winds stay up overnight (generally light out of the south to southwest). This will lead to warmer overnight low tonight, with temps possibly even rising a few degrees after midnight across the western portion of the area as cloud cover increases. Thus, expect low temps will generally range from around 30 in the usual rural cold spots to the mid 30s in the urban areas. && .SHORT TERM / TUESDAY AND TUESDAY NIGHT/... As of 300 PM Monday... ...Gusty NW winds to 25-30 mph with wind chills in the 10-15 degree range Tuesday evening... The main cold front and upper level feature will move across central NC between 12z and 18z. This is when the mid and high level moisture will increase enough for variably cloudy skies. Once the cold front passes, winds will shift to the WSW and increase to 15-20 mph with gusts to 30 mph. CAA will be delayed a few hours behind the front due to the strong westerly downslope component. Guidance is robust in warming temperatures well into the mid 50s to lower 60s in the east, with highs 50-55 NW. Expect a very sharp drop in the temperatures late Tuesday and Tuesday evening with strong cold dry air advection. Readings will slip below freezing within a few hours of sunset in the Triad, and by late evening in the Triangle. Mainly clear skies and diminishing winds are expected late Tuesday night. Lows will be in the lower to mid 20s. Wind chill readings of 10-15 are likely from mid evening through the early morning hours. && .LONG TERM /THURSDAY THROUGH MONDAY/...
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As of 300 AM Tuesday... Predominantly zonal flow aloft mid week will slowly transition to weak troughing in the east by mid day Friday. Several waves of energy will rotate along the trough axis out of the upper mid west during the long term period. The first system should pass just to our north Thursday morning, introducing only a short period of enhanced cloud cover to the northern piedmont counties. A second, much stronger wave, will rotate around a digging trough axis Friday night into Saturday, bringing a surge of much cooler temperatures and enhanced POPs to the area. This wave looks to initiate the frontogenesis process just off the VA/NC coast, keeping most of the precipitation offshore. This trend will be worth keeping an eye on though, as faster development could see POPs sneak a bit further west into our coastal plain counties. A brief period of high pressure builds in from the south Saturday into early Sunday, allowing southerly to southwesterly flow, along with near normal temperatures to reestablish ahead of an approaching cold front set to move through early Monday.
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&& .AVIATION /06Z TUESDAY THROUGH SATURDAY/... As of 110 AM Tuesday... High confidence in VFR conditions for the next 24 hours across all of central NC. But a surge of strong and gusty winds today may lead to handling difficulties with aircraft this afternoon through tonight. A dry cold front and potent upper level trough will cross the area today, bringing a period of VFR cigs with cloud bases over 5,000 ft AGL and unrestricted vsbys. Surface winds will veer from SW to WNW and NW with frontal passage, occurring around 14-15z at INT/GSO and 15z-18z at RDU/RWI/FAY. Sustained speeds post-front of 12-17 kts, with gusts to 22-28 kts, are likely, continuing through much of tonight as colder air pours into the area. Looking beyond 06z Wed, surface winds will decrease overnight and back to WSW by daybreak Wed. VFR conditions will hold through Wed, then the approach and passage of an upper level disturbance across VA and northern NC may bring a period of cigs (likely VFR but may be briefly high-end MVFR) Wed night with a possible flurry. VFR conditions should then dominate Thu through Sat, although yet another disturbance may bring a period of MVFR cigs Fri. -GIH && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Hartfield NEAR TERM...BSD SHORT TERM...Badgett LONG TERM...JJM AVIATION...Hartfield is the U.S. government's official web portal to all federal, state and local government web resources and services.