247 FXUS61 KRNK 062305 AFDRNK Area Forecast Discussion National Weather Service Blacksburg VA 605 PM EST Sun Jan 6 2019 .SYNOPSIS... A weak cold front will drift south through the area overnight before stalling across the Carolinas Monday. High pressure will slide east across New England Monday and wedge south along the mountains into Monday evening. Another frontal system will arrive Tuesday, followed by a secondary Arctic front that should bring much colder air on strong northwest winds for mid week. && .NEAR TERM /THROUGH MONDAY/... As of 258 PM EST Sunday... Northwest flow aloft will prevail across the area tonight on the back side of the closed low pushing northeast into the Atlantic ocean. High pressure centered over the Great lakes this afternoon will slide east tonight into Monday. Winds will diminish this evening and will decouple in the valleys tonight, but remain up or higher across the ridges. Strong northwest flow aloft orthogonal to the Alleghany front and Blue Ridge mountains, along with a notable inversion around 850mb in an otherwise dry sounding will continue the orographic cirrus tonight. Some upslope clouds may persist in the west tonight into Monday morning. Low temperatures tonight will range from around 30 degrees in the northern mountains to the mid to upper 30s in the piedmont. Wedge of high pressure will be in place east of the Appalachians on Monday with associated east to southeast flow producing plenty of clouds and maybe some light rain or drizzle up along the Blue Ridge Monday afternoon into Monday night. High temperatures on Monday will vary from the mid 30s in the northern mountains to near 50 in the piedmont. && .SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/... As of 240 PM EST Sunday... Surface high will be positioned offshore at the beginning of this period with a warm front tracking across the southern and central Appalachians. Weak in-situ wedge will erode as this occurs. Will see light rain chances with some converge along the warm front along with some upslope along the mountains, but overall pops will be in the low to slight chance range. Tuesday, models are a little off in timing of cold frontal passage with the 12z ECM faster than the GFS. Still overall looking as westerly flow takes shape, shower chances will be situated more of the mountains, with fairly dry east of the Alleghanys. Tuesday looks to be our last mild day for a while, as upper pattern changes with deepening trough over the east with northwest flow allowing arctic air to slide southeast into the region Wednesday. Disturbances in the upper flow and good low level trajectories off the Lakes will be enough to keep snow showers in the forecast for the mountains of WV into some of the VA/NW NC mountains late Tuesday night into Wed night, though favorable set up stays more over the central Appalachians, north into PA/OH. A few inches are not out of the question from Tue night into early Thursday over the mountains of SE WV. Another wind event possible but this time, fairly strong cold advection will help with the winds, though models showing pressure rises being limited. So for now will mention possible strong winds in the HWO along and just west of the Blue Ridge midweek. After highs in the 50s to lower 60s Tuesday, temperatures on Wednesday will be at or below normal with highs in the lower to mid 30s in the mountains to mid 40s southside VA into the piedmont of NC. Confidence in this forecast is high for the pattern change but low to medium on snowfall amounts, and medium on wind speeds. && .LONG TERM /THURSDAY THROUGH SUNDAY/... As of 1250 PM EST Sunday... Guidance seems to be in decent agreement early this period as upper low shifts further away from the east coast into the Canadian Maritimes. Still a broad northwest flow will bring colder and dry air in across the region, which will be a change from what have been experiencing so far this month. Snow showers/flurries are going to fade by Thursday morning in the upslope areas. Southern stream energy sets up Friday and Saturday, but models diverge here, but in essence the trends have the main surface low tracking from southern TX Friday evening into the Gulf of Mexico by Sat evening with surface high situated from the Great Lakes into the mid-Atlantic. Will see some increasing clouds with frontal boundary stretched along the Gulf Coast but how far north the precip shield gets will the question as flow aloft looks more confluent over our area which tends to squelch any northward shift and causes more subsidence. Still the weekend shows potential for precip as low forms off the southeast coast, but this is due to northern stream energy slipping in and aiding in development of this low with southern stream shortwave weaker. So for now inclined to keep low chance pops across the southern tier of the forecast area, roughly south of U.S. 460 Sat-Sun, where snow will be possible. GEFS ensemble from 06z showing some snow accumulation potential but most of the members are on the low end. && .AVIATION /00Z MONDAY THROUGH FRIDAY/... As of 600 PM EST Sunday... VFR conditions will prevail into tonight under passing high clouds that will arrive from the northwest as a weak surface cold front drifts south through the region. Added jet energy aloft looks to also continue the trend of rounds of mid/high clouds into Monday as high pressure wedges in from the north. However most cigs are expected to remain VFR espcly east of the mountains into Monday afternoon. The exception may be late tonight into at least midday Monday for locations across the mountains where low level southeast upslope flow may result in an axis of lower clouds especially across the northwest North Carolina and Southwest Virginia mountains. However lots of uncertainty given dry air, but if lower cigs do evolve then sub-VFR cigs along with vsby restrictions in patchy fog may occur. Westerly winds under 10 kts tonight will turn east to northeast behind the passing cold front overnight. Winds will then veer more southeast at 5 to 15 kts Monday with gusts to 20-25 kts possible KBLF vicinity Monday afternoon. Extended Aviation Discussion... An increase in MVFR cigs can be expected by Monday evening as another weak cold front looks to bring MVFR in lower cigs and showers across the mountains Monday evening into early Tuesday. These MVFR ceilings would be primarily limited to areas west of the Blue Ridge. Gusty westerly winds are expected again Tuesday afternoon as drier, colder air advects into the region from the northwest. VFR should prevail east of the Blue Ridge with downslope northwest winds, but MVFR ceilings could linger in the west due to upslope conditions. Northwest flow aloft will push a secondary front into the area by Wednesday with more gusty northwest winds and upslope sub-VFR cigs. Snow showers and brief periods of IFR-LIFR conditions may occur in the western mountains mid week, but elsewhere it should remain MVFR at the worst and largely VFR for the later half of the week. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...None. NC...None. WV...None. && $$ SYNOPSIS...JH/KK NEAR TERM...KK SHORT TERM...WP LONG TERM...WP AVIATION...JH/KK/RAB