Area Forecast Discussion
Issued by NWS Blacksburg, VA

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000 FXUS61 KRNK 092345 AFDRNK Area Forecast Discussion National Weather Service Blacksburg VA 645 PM EST Fri Dec 9 2016 .SYNOPSIS... High pressure will build across the Mid-Atlantic region tonight through Saturday. The associated cold airmass will remain over the area through early Sunday before beginning to moderate. A cold front will approach the area late Sunday night and Monday. && .NEAR TERM /THROUGH SATURDAY/...
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As of 632 PM EST Friday... Upslope stratocu should hang tough into early overnight with yet another shortwave swinging by late. A blend of the 18z NAMDNG and 12z CMC showed a good blend on how sky cover will transition this evening. As far as snow showers/flurries, as usual radar beam overshooting the lower clouds across the mountains of WV, but expect a few more hours of light snow showers or flurries north of Lewisburg toward the Pocohontas line. The rest of the area will clear and winds subsiding will allow temps to drop quickly overnight. Adjusted temps down a bit based on this forecast. Previous afternoon discussion... In the wake of this morning shortwave, drier air will push in across the region this afternoon into tonight and taper off light snow showers and snow flurries across the western mountains. High pressure over the Midwest will build southeast tonight into Saturday. Blustery northwest winds this afternoon will gradually subside tonight. This in combination with mostly clear skies will allow for ideal radiational cooling conditions, promoting low temperatures from the upper single digits for the highest elevations, such as Mount Rogers to the lower 20s in the Piedmont. With pressure centered over the Appalachians on Saturday, it will be cold with high temperatures averaging 10 to 15 below normal with readings from the mid 20s in the northwest mountains of Greenbrier county to the lower 40s along the eastern slopes of the southern Blue Ridge mountains.
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&& .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/... As of 300 PM EST Friday... High pressure over the region Saturday night will push off to our east and allow significant isentropic lift to develop in the return flow as a low moves through the Great Lakes region and pushes a cold front in our direction. The upper flow is low amplitude and progressive will not add much in the way of dynamic lift, but a plume of moisture surging up through the piedmont late Sunday/Sunday night may help generate some showers ahead of the main body of precipitation associated with the approaching cold front. While temperatures will be steady to rising Sunday night, temperature profiles support the possibility of some freezing rain at the higher elevations from western Greenbrier through the Alleghany Highlands with a light glaze possible before going over to all rain Monday morning. Winds may also become gusty along the ridges Sunday night into Monday but the warm air advection pattern will inhibit downward momentum transfer of higher winds to lower elevations. The bulk of precipitation will arrive in the west toward daybreak Monday and move across the region from west to east into Monday afternoon. Lingering upslope precipitation west of the Ridge will transition to some wet snow across western Greenbrier with no accumulation expected. With the progressive pattern and transitory nature of weather systems into early next week, expect temperatures to be variable. Readings will be below normal Sunday followed by a warming trend as the high shifts to our east and winds become southerly with above normal readings on Monday. However, temperatures Monday will be falling behind the cold front as it moves through from west to east. && .LONG TERM /TUESDAY THROUGH FRIDAY/... As of 300 PM EST Friday... The upper pattern will remain progressive as a large closed low digs into eastern Canada and keeps the Appalachians and central mid Atlantic region in essentially zonal flow. So after a brief period of relatively quiet weather under high pressure on Tuesday, the next weather system will begin to affect our area very late Tuesday night. Strong isentropic lift will develop over an in-situ wedge as a complex low approaches from the southwest. There may be some p-type issues at the higher elevations with the initial surge of warm air advection late Tuesday night through the first part of Wednesday. However, a significant surge of cold air will start moving in during the day Wednesday behind the departing low and transition precipitation to snow, especially in upslope areas west of the Blue Ridge. There may also be some freezing issues as the cold air arrives on blustery winds and interacts with wet surfaces Wednesday night. Lingering snow showers west of the Ridge will dissipate as cold high pressure builds in through the end of the workweek. Temperatures will generally exhibit a cooling trend for most of next week with highs on Tuesday well above normal, falling to well below normal by Thursday. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
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As of 632 PM EST Friday... Ceilings will stay MVFR at BLF/LWB this evening but we should see VFR at LWB around midnight, while BLF appears to hang on at times to MVFR until 10-12z. At times BLF will scatter out but confidence is high enough to maintain bkn most of the night. Rest of the terminals will stay VFR with clear skies. High pressure will pass overhead Saturday promoting light winds and clear skies. VFR conditions will prevail Saturday into Saturday night. High confidence in ceilings, visibilities and winds during the taf period. Extended aviation discussion... Next weather system to follow will be a cold front, models suggesting a Sunday Night arrival which will likely produce sub- VFR conditions at times, and possibly wintry mix in the mountains. The cold front crosses the area Monday with continued threat of showers and sub-VFR at times, then somewhat of a break Monday night and maybe Tuesday, with another system arriving midweek with more precip, and more than likely sub-VFR at times.
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&& .RNK WATCHES/WARNINGS/ADVISORIES... VA...None. NC...None. WV...None. && $$ SYNOPSIS...KK/PM NEAR TERM...KK/WP SHORT TERM...MBS LONG TERM...MBS AVIATION...KK/PM/WP is the U.S. government's official web portal to all federal, state and local government web resources and services.