Area Forecast Discussion
Issued by NWS Blacksburg, VA

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000 FXUS61 KRNK 130842 AFDRNK Area Forecast Discussion National Weather Service Blacksburg VA 442 AM EDT Tue Mar 13 2018 .SYNOPSIS... A strong upper level system will keep us colder than normal into midweek bringing snow showers to the mountains during this time. This upper system loses its grip on us by the end of the week, and closer to normal temperatures returns. && .NEAR TERM /THROUGH TONIGHT/... As of 420 AM EST Tuesday... Expect nuisance type winter weather this morning with a scattering of snow showers in the upslope areas starting to wane, but with melted snow turning to ice, slick travel will persist until mid to late morning. Will see an upper low swing southeast out of the Great Lakes this morning, deepens and shift east over NY/PA tonight. This will send a strong vort lobe across the southern Appalachians tonight, with favorable dynamical support for a round of snow showers, especially on the western slopes of WV into far SW Va. As the air cools, expect snow to liquid ratios to go to 15 to 20:1, and with forecast liquid equivalent of a tenth to a quarter inch, areas from Tazewell to western Greenbrier should see about 2 to as much as 6 inches of snow. Therefore, have added Summers, Mercer and Tazewell to the winter weather advisory, which will run until 8am Wednesday. With the strength of this system will not be surprised to snow flurries or light snow showers make it into the VA/NC piedmont late tonight. Bands of snow showers are likely to bring down a quick in anywhere along/west of the Blue Ridge Tuesday night. Otherwise, continued chilly and a little brisk in the mountains this morning, with sunshine returning to the lee of the mountains. High temps will run 10-20 degrees below normal, ranging from the lower to mid 30s mountains, to mid 40s piedmont. Tonight, temperatures sink into the 20s, with some teens possible in the mountains. && .SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/... As of 330 AM EDT Tuesday... A deep trof over the eastern US will keep persistent northwesterly flow with some snow showers west of the Blue Ridge before it finally loses its grip on the region by the end of the week. Wednesday night into Thursday a weak low supported by a short wave rotating through the upper trof will bring some isentropic lift on west to northwest flow, rejuvenating a chance for snow showers west of the Ridge. A weak front extending from low pressure over the midwest will sink through the region late Thursday night into Friday with a chance of mixed rain and snow showers mainly for the mountains of North Carolina into the Mountain Empire of Virginia. The main concern through the latter portion of the week will be the potential for high winds as the low level wind field steadily increases starting on Wednesday. Diurnal mixing on both Wednesday and Thursday will allow for steep low level lapse rates and efficient downward momentum transfer so expect conditions to be quite gusty. Will have to see how much cloud cover there to impede heating and hinder mixing, especially west of the Ridge. Higher elevations will likely keep some wind at night as well. Will continue to highlight these parameters in the hazardous weather outlook and see if later runs support the need for a wind advisory. Temperatures will be well below normal on Wednesday, with a rapid moderation to near normal conditions by Friday. && .LONG TERM /SATURDAY THROUGH MONDAY/... As of 250 PM EDT Monday... High pressure will keep the area dry through Saturday night. A warm front aloft is expected to move over this weakening high pressure on Sunday. A second stronger warm front will move over the region on Monday. Both of these systems will bring light rain into the area. && .AVIATION /09Z TUESDAY THROUGH SATURDAY/... As of 120 AM EDT Tuesday... Expect VFR conditions to prevail east of the upslope areas of West Virginia, into southwest Virginia this morning, so zeroing in on MVFR to possibly IFR cigs at BLF/LWB with off and on snow showers. Overall, trends of the models showing the lower cigs rising to VFR between 15-17z. Will see occasional wind gusts to 20 kts at ROA/BCB/BLF/LWB through the morning, possibly into the afternoon, though gradient starts to relax a bit after 19z. Another upper impulse moves in toward the end of this taf period bringing another round of snow showers to BLF/LWB, with sub-VFR likely. Extended Aviation Discussion... The western mountains will see lingering MVFR conditions with upslope clouds and snow showers through Wednesday, with VFR conditions east of the Blue Ridge. Conditions are expected to improve in all areas by the weekend with a notable warming trend. && .EQUIPMENT... As of 430 AM EDT Tuesday... The Mount Jefferson NWR will remain off the air until further notice awaiting a part that was damaged during a high wind event/power outage over a week ago. Inclement winter weather could further delay the repair of this site until midweek. Richlands NWR is working. Please seek alternate sources for your weather information, such as adjacent NWRs (Roanoke, Hinton WV, Lynchburg, South Boston, Johnson City TN, Beckley WV, etc.), commercial sources, and the internet. You can always access our web page at && .RNK WATCHES/WARNINGS/ADVISORIES... VA...Winter Weather Advisory until 8 AM EDT Wednesday for VAZ007. NC...Winter Weather Advisory until 10 AM EDT this morning for NCZ001>006-018>020. WV...Winter Weather Advisory until 8 AM EDT Wednesday for WVZ042- 043-508. && $$ SYNOPSIS...AMS/WP NEAR TERM...WP SHORT TERM...MBS LONG TERM...RCS AVIATION...KK/WP EQUIPMENT...AMS/RAB is the U.S. government's official web portal to all federal, state and local government web resources and services.