Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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000 FXUS62 KRAH 111625 AFDRAH Area Forecast Discussion National Weather Service Raleigh NC 1125 AM EST Mon Dec 11 2017 .SYNOPSIS...
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High pressure will extend over the Gulf of Mexico and southeast states today through tonight. A cold front will cross North Carolina Tuesday, bringing much colder temperatures Tuesday night through Wednesday.
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As of 1120 AM Monday... Sunny skies were observed across all of NC late morning. The temperatures have become milder as the cold air mass continued to gradually modify. The only thing of note on the visible satellite data was the remaining snow cover that shows up across all the mountains and northwest part of NC, as far SE as the Piedmont Triad. Cloudiness associated with the next fast moving clipper type low was observed over the Ohio Valley. It will be very late today before the cloudiness increases over NW parts of the area. Highs should range in the lower to mid 50s, except upper 40s in the Triad where some of the sun`s energy continued to be used to melt the residual snow and ice. Attention turns to the potent mid level clipper diving SE over the Upper Midwest this morning. This wave, and its accompanying surface cold front, will drop SE then E into the mid Miss Valley and Ohio Valley through tonight. As it approaches, we`re likely to see increasing mid clouds tonight, especially across the NW and N, with weak moist upglide noted on the 310K surface. Improving low level moisture, especially over the NW CWA, may induce patchy stratus as well overnight. The trend to partly to mostly cloudy skies and the light SW breeze holding up overnight should temper cooling somewhat, yielding lows of 30-36, not far from normal but much milder than the last couple of nights. -GIH
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&& .SHORT TERM /Tuesday through Tuesday night/... As of 310 AM Monday... The upper level shear axis and corresponding dry surface cold front will traverse the area Tuesday, arriving in the mid morning W, and shifting east of the area during the mid afternoon. Skies should remain partly to mostly cloudy through the morning, with a gradual improving trend to fair to partly cloudy skies in the afternoon, with a combination of thin mid and high clouds along with flat cu as moisture is trapped near the top of an increasing boundary layer mixed depth. The cooler air mass will be building in from the west, such that it appears that the mountains will initially block the coldest air, and we should still reach highs from the upper 40s NW to the mid 50s SE, although a stout breeze with frequent gusts around 20 kts will make it feel chillier, especially late in the day as the dewpoints plummet. While the initial cold front will be moving to our east by mid afternoon, the more prominent cold/dry air surge will arrive late Tue afternoon through the evening, as a strong vorticity max dives through the trough base across NC, with the dynamic trop dropping to around 650 mb. Some enhanced cloudiness and perhaps a burst of stronger wind gusts may accompany this trough passage. Otherwise, skies will clear out Tue night, and temps are expected to bottom out in the 20-25 range. These readings with a steady NW breeze will bring the wind chill down into the low teens over much of the area. -GIH && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... As of 230 AM Sunday... The quieter weather pattern continues mid week, as general troughing in the east gives way to a more zonal pattern toward the end of the period. Wednesday looks to be the coldest day across central North Carolina, with afternoon highs failing to reach the 40 degree mark under a brisk northwest wind. Southerly to southwesterly flow returns early Thursday, allowing a brief warmup to more seasonable temperatures to take place. Around this same time, an area of low pressure looks to develop off of the Carolinas, introducing shower chances into the forecast Friday afternoon and evening. Model differences take hold at this point, with a much wetter and more amplified GFS model introducing an additional wave or two of precipitation to the region before the end of the weekend, while a much drier ECMWF keeps us under high pressure. For now, have limited shower activity at the end of the period until better consensus is observed. && .AVIATION /12Z Monday through Friday/... As of 640 AM Monday... With one exception, VFR conditions are a near certainty for the next 24 hours, as a surface high pressure ridge extends into the area from the WSW. Vsbys will be unrestricted through this evening, with no cigs. Starting soon after midnight, an approaching front will bring scattered mid clouds based above 12,000 ft AGL, as well as a risk for cigs below 1,000 ft AGL at INT/GSO after 08z. In addition, a low level jet from the southwest may bring LLWS conditions to FAY late in the period (after 09z). Otherwise, surface winds will be light, under 8 kts, from the W, shifting to SW then S late today into tonight. Looking beyond 12z Tue: A dry cold front will move through the area on Tue, but VFR conditions should hold. Winds will shift back to northwesterly after frontal passage Tue, and gusts up to 20-25 kts are possible from late Tue morning through much of Tue night. VFR conditions will dominate through at least Thu night. Sub-VFR conditions are possible with rain chances increasing Fri as an upper trough approaches. -GIH && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Hartfield NEAR TERM...Badgett/Hartfield SHORT TERM...Hartfield 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.