... A cold front will cross the region tonight and be followed by high pressure which will settle over the area by Sunday. A weak cold front will cross the area on Monday, followed by another weak to moderate system Wednesday into Thursday. High pressure returns for Friday.
NEAR TERM /THROUGH SATURDAY/... As of 200 PM EST Friday...
A moisture rich atmosphere was in place across the area as noted off the 12Z RNK Sounding with a Precipitable Water value of 0.78 inches. A look at SPC's Sounding Climatology Pages shows this value a little above the 90th percentile for this time of year. This deep moisture is being advected upslope on southeast winds wrapping into an area low pressure approaching the region from the west. Winds at 850mb were still in the neighborhood of 35 to 45 kts, and were still getting gusts over parts of the Wind Advisory area in the 45 to 50 mph range. The site most often in this range this afternoon has been Banner Elk, NC. The Wind Advisory continues until 600 PM. This timing still looks good, as it is right around the time the overall low level pattern changes with the passage the arrival and passage of the cold front, and a shift of low level winds to the southwest, then west, along with a notable decrease in speed.
Heading through the remainder of the afternoon, precipitation will continue to be greatest across the western half of the region. Here a broad band of shower was streaming from south to north, with a gradually shift to the east. This area was being following behind closely by precipitation coincident to the actual front. This band of showers was currently over eastern Kentucky, and should be arriving across the western half of the region early this evening. Please reference the HYDROLOGY section of this discussion for additional details about tonight's precipitation.
As the precipitation exits the area to the east late tonight, residual moisture, increasing cold air advection, a non-zero vector of an upslope component across the western section of the area will allow for isolated to scattered snow showers. As mention, the trajectories will not be maximized for the best upslope, but they will be there do some degree, and will continue in such a way through the day Saturday. Areas west of a line from Bluefield, WV to Lewisburg, WV can expect some light snow accumulation. Likewise, some of the higher terrain of the Mountain Empire region of southwest Virginia, south into the Northern Mountains of North Carolina may also see some light snow accumulation. Any location that does receive snow accumulation most like will receive under one inch.
SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/... As of 208 PM EST Friday...
The closed upper low over the St. Lawrence River Valley Saturday night will lift northeast into Sunday. Moisture around the upper low will continue snow showers and snow flurries in the western mountains. Snow accumulations will vary from a coating to around an inch in western Greenbrier county. Low temperatures Saturday night will range from the mid 20s in the mountains to the lower 30s in the piedmont.
As the low moves away Sunday, the upslope snow showers will taper back to western Greenbrier county in southeast West Virginia. It still will be breezy with 15-25 knot gusts along the highest ridgetops. Additional snow accumulation will be light from a trace to around an inch. High temperatures on Sunday will vary from the lower 30s in northwest Greenbrier county to the lower 50s in the piedmont.
By Sunday night, a weak shortwave trough pivoting around the periphery of the departing upper level low should approach from the west with the opportunity for upslope snow showers. Increased pops to allow for isolated to scattered generally west of interstate 77. Low temperature Sunday night will generally be from the mid 20s in the west to the lower 30s in the east.
The shortwave will pass overhead Monday and push moisture across the area. Some light rain may try and push east across the piedmont. It will have to overcome the downsloping east of the Blue Ridge. With the trend of the models been wetter, introduced some light pops. High temperatures Monday will warm into the lower 30s in the northwest mountains to around 50 degrees in the piedmont.
Isolated snow showers may linger in the western mountains Monday night from southeast West Virginia to the northwest North Carolina. Low temperatures will drop into the upper 20s to lower 30s Sunday night.
Moderate confidence in the short term period.
LONG TERM /TUESDAY THROUGH THURSDAY/... As of 228 PM Friday...
High pressure will build overhead Tuesday and slide east Tuesday night. Cloud cover will gradually increase Tuesday night into Wednesday ahead of the next system. The GFS and ECMWF are slowly converging on a solution with the handling a southern system. A weak low pressure will travel across the Lower Mississippi Valley and into Florida. An area of low pressure may develop along the East coast and lift north this weekend. There still remains model to model and run to run differences with this system. The details of the forecast will become more clearer with time.
Low to moderate confidence in the long term period.