Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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000 FXUS62 KRAH 242110 AFDRAH Area Forecast Discussion National Weather Service Raleigh NC 409 PM EST Tue Jan 24 2017 .SYNOPSIS... Mild high pressure will build into the area in the wake of the deep low pressure system lift northeast up the northern Mid Atlantic coast. A cold front will push east across Central NC on Thursday. && .NEAR TERM /THROUGH TONIGHT/... As of 320 PM Tuesday... Northwest flow this afternoon between a low off the New England coast and a ridge of high pressure nearing the Tenn Valley. Wind gusts will abate this evening as the ridge shifts east overhead, with just light winds or calm conditions overnight. Thicknesses rise overnight, but clear skies will promote near optimal cooling, especially southwest, yielding lows in the low to mid 30s. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/... As of 320 PM Tuesday... Shortwave ridging overhead Wednesday morning will shift east as the leading edge of the western US trough approaches. A southwest wind will result in a 35m rise in thicknesses to around 1370m, suggesting highs in the low to mid 70s. Forecast sounds, however, show relatively shallow mixing and not all of the warmth aloft being realized. The pattern supports warmer temps, so will go with warmer guidance and 69-73 for highs. High clouds will increase Wednesday night ahead of the trough as the somewhat sheared but still strong vort max approaches. Moisture return is limited, but 90-120m height falls look to be sufficient to produce a band of scattered to numerous light showers moving into the Piedmont late Wednesday night. Temps will remain mild and likely above guidance given a prefrontal southwest wind around 10kt and increasing clouds; 50-54. && .LONG TERM /THURSDAY THROUGH TUESDAY/... As of 400 PM Tuesday... The models have trended slightly slower, relative to previous solutions, with the passage of a cold front through central NC early Thu. A quick-hitting warm conveyor belt, with moisture confined mostly below 700 mb --and embedded band of showers-- will move E across the Ern two thirds of the RAH CWA through midday. Limited CAA initially behind the front, and downslope flow, will result in another mild day, with high temperatures expected to range from the mid 50s W to mid 60s E. PeaK wind gusts, up to 30-35 mph, will likely not develop until the early day clouds, showers, and shallow mixing move E, and the boundary layer deepens from W to E during the afternoon. Behind this lead front, and beneath a broad trough aloft forecast to migrate into the Ern U.S., temperatures will cool to more seasonable/average levels through early next week. There remains significant model spread regarding the amplitude of a Nrn stream shortwave trough in NW flow aloft, as it passes through the base of the L/W trough over the Middle Atlantic states late Sun-Mon. Typical of the passage of most NW flow disturbances, this feature will most likely be a dry one for central NC. Nonetheless, some very light precipitation may result from otherwise mid level ceilings and virga; and boundary layer temperatures over the (Wrn) Piedmont may support light snow if it 1)indeed precipitated, and 2) did so when temperatures were coldest early Mon - both low predictability and probability outcomes given the time range and large model spread. && .AVIATION /20Z TUESDAY THROUGH SUNDAY/... As of 115 PM Tuesday... Northwesterly winds around 15kt, gusting to around 25kt, will continue this afternoon and then diminish as by 00Z as high pressures edges into the region. Winds overnight will be light and southwesterly, or calm, with clear skies and VFR. VFR will continue on Wednesday while a 5-10kt southwesterly wind develops. Looking ahead: VFR conditions are expected through Wednesday. A cold front will cross the region late Wednesday night/early Thursday, bringing with a chance of rains and what areas to be mainly MVFR/IFR ceilings to the area. VFR conditions should return late Thursday afternoon/evening. && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...CBL NEAR TERM...SMITH SHORT TERM...SMITH LONG TERM...MWS AVIATION...SMITH is the U.S. government's official web portal to all federal, state and local government web resources and services.