Area Forecast Discussion
Issued by NWS Blacksburg, VA

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000 FXUS61 KRNK 111424 AFDRNK Area Forecast Discussion National Weather Service Blacksburg VA 924 AM EST Tue Dec 11 2018 .SYNOPSIS... High pressure from the Ohio Valley to the Lower Mississippi Valley with move southeast today and tonight as a weak cold front sweeps across the northeast United States. Low pressure developing in the Plains Wednesday night will track across the southern United States Thursday and Friday and will reach the Mid Atlantic area Saturday. && .NEAR TERM /THROUGH TONIGHT/... As of 925 AM EST Tuesday... Extended winter weather advisory North Carolina to account for slower rise in temperatures this morning. Modified temperatures this morning utilizing the latest surface obs, their trends and shaped late morning towards GLAMP. In general, with snow pack temperatures are running colder this morning. The rise in temperatures will be slower this morning into this afternoon. Plan to watching temperature trend this morning with potential adjustments on Highs for this afternoon. More changes later this morning... As of 300 AM EST Tuesday... No changes planned to Winter Weather Advisory. GOES Land surface skin temperature image and surface observations showed temperatures in the Greenbrier Valley from Greenbrier County into Monroe County, and in spots of Tazewell County and from Pulaski County up through Rockbridge County in the single digits. Mesonet site at Burkes Garden had cooled to -6 as of 2AM. This was largely a combination of little to no cloud cover, light to calm wind and snow cover. Similar conditions tonight are expected so will be lowering minimum temperatures well below guidance in the favored locations, with a large temperature spread between the highest elevations and the sheltered valleys. Any mid and high clouds coming in from the west will not reach the area until late tonight. 500MB trough over the eastern United States moves east today leaving the Mid Atlantic region in broad northwest flow through tonight. At the surface a weak front crosses through the northeast United States today. Colder air at 850MB comes in behind the front this afternoon and evening along with a northwest low level jet around 50 knots. Bufkit forecast soundings momentum transfer showed the potential for gusts of 20 to 30 mph this afternoon, especially at higher elevations, with the low level jet remaining above the inversion. Winds decouple after sunset. Current areas of low clouds and fog along the western slopes of the central Appalachians from West Virginia into western Tennessee is shallow and will dissipate rapidly after sunrise. NAM and GFS suggest status and fog may develop in the upslope areas of southeast West Virginia again tonight. && .SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/... As of 300 AM EST Tuesday... High pressure will bring quiet weather to the Appalachians and central mid Atlantic region on Wednesday. A frontal system will then bring a few flurries to southeast West Virginia as it brushes the region Wednesday night. Thursday looks to be dry, but by Thursday night a deep upper closed low will start driving low pressure out of the Mississippi valley with a chance of precipitation spreading into the region from the southwest late Thursday night/early Friday morning. There may be some mixed precipitation/freezing rain initially as the precipitation moves in, but it looks to be brief without any appreciable accumulation. Excellent moisture transport and synoptic lift will then bring periods of heavy rain to the area Friday and Friday night until an occluded front moves through late Friday night. The low level winds field will also become quite robust ahead of the approaching low with some strong wind gusts possible for the higher elevations west of the Blue Ridge into the Mountain Empire region. Ensemble clustering indicates better than average confidence for rainfall totals of 1 to 2 inches mainly from the Blue Ridge eastward. Combined with recent snowmelt there is growing concern for potentially significant flooding Friday and continuing into the weekend. This is definitely something to keep an eye on over the next couple of days especially for anyone with interests near streams, creeks, and rivers. Temperatures will remain below normal through the end of the week. && .LONG TERM /SATURDAY THROUGH MONDAY/... As of 200 PM EST Monday... Precip winds down somewhat into Saturday with models keeping low level temps warm enough for mainly rain showers. With model showing more disagreement over the weekend kept close to the ensembles and previous forecast with smaller chance of mountain rain or snow showers Sunday into Monday with northern stream system possibly arriving early next week. Temperatures this weekend will actually be at or just above normal. && .AVIATION /14Z TUESDAY THROUGH SATURDAY/... As of 650 AM EST Tuesday... Lingering moisture over snowpack and weak upslope in eastern Kentucky and West Virginia had resulted in areas of IFR to LIFR stratus/freezing fog early this morning. Surface and low level winds will be out of the northwest today behind a weak cold front. Some of the winds will mix down to the surface this afternoon with gusts of 20 to 30 knots in the mountains. Otherwise Bufkit showed the strongest part of the low level jet remaining above the inversion. Have included some LLWS in the TAFS due to this jet. Fog and stratus will dissipate quickly after sunrise this morning. VFR conditions are expected for the rest of the day across southwest Virginia, northwest North Carolina and southeast West Virginia. Winds in the valleys will decouple again this evening. More low clouds are possible in the upslope areas of southeast West Virginia, but have left out of KLWB and KBLF for now. Extended Aviation Discussion... A strong low tracks across the southern United States at the end of the week. There are some timing differences in the models but at this point the best chance of rain and associated MVFR conditions in the Mid Atlantic region will be Thursday night into Friday as the surface low and its associated cold front cross the area. Upper low may then linger Friday night into Saturday with potential MVFR lingering to start the weekend. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...None. NC...Winter Weather Advisory until noon EST today for NCZ001>003- 018-019. Winter Weather Advisory until 11 AM EST this morning for NCZ004>006-020. WV...None. && $$ SYNOPSIS...AMS NEAR TERM...AMS/KK SHORT TERM...MBS LONG TERM...MBS/WP AVIATION...AMS/JH is the U.S. government's official web portal to all federal, state and local government web resources and services.