... Dry and cooler high pressure will build over the region through Friday in the wake of a departing cold front. Another cold front will arrive from the north on Saturday and settle south of the area through Sunday. The boundary will return northward as a warm front early next week, keeping the weather unsettled.
NEAR TERM /THROUGH TONIGHT/... Expect low to moderate gusts to continue into mid day across the NC mtn valleys holding wind chill values in the teens through the morning hours. At elevations abv 4.5 Kft, llvl CAA and momentum transfers have produced wind gusts in the 40-50 mph range dropping wind chills below zero, which will warm above freezing by the later morning.
The upper pattern transitions from a cyclonic trof to broad ridging thru the period. The FA will remain in a stg subs zone today as soundings show very dry/dense air aloft. This will keep things quite dry with some Ci traversing the upstream ridge axis. This cloud cover wont impact heating much as insol remains pretty high, yet with temps starting the day well below climo, a seasonal diurnal curve will yield high temps about 8-10 degrees below normal. Surface winds will continue to weaken this afternoon as broad hipres begins to center across the region. Min temps fall below normal tonight due to efficient rad cooling with lows similar, yet a few degrees warmer, to this morning's values.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... As of 305 am Thursday: The cool/dry weather will continue into the early part of the short term, before temperatures begin to modify early in the weekend. This will occur as clouds and moisture increase in association with a warm advection regime becoming established across the southern Appalachians and vicinity in advance of a cold front. Precip chances associated with the WAA pattern followed by passage of the front will ramp up PoPs to the chance range across much of the CWA by 12Z Saturday...peaking in the 40-60% range across much of the area (with the highest chances being along the TN border) late Sat morning before chances diminish through the remainder of the day as the front sags south of the area. Dry weather is expected to persist through early Sunday, although clouds will persist to some degree, as low level moisture remains plentiful with the front becoming increasingly quasi-stationary and stretched in a zonal configuration just south of the region. Temps will be above normal Fri night and Sat...and still above normal Sat night, but much closer to climo as cooler air returns in the wake of the front.
LONG TERM /SUNDAY THROUGH WEDNESDAY/... As of 320 am Thursday: A rather complex upper pattern will become established across the Conus during the extended, featuring a split flow regime, with a series of storm systems impacting the West Coast in the southern stream (which will otherwise remain somewhat inactive across the remainder of the country), and a very active northern stream, with multiple potent short wave troughs forecast to rotate across the northern quadrant of the country through the period. With the upper flow remaining quasi-zonal across the Southeast, a baroclinic zone will remain somewhat stationary to our south early in the period. However, the occasional disturbances passing north of our area will likely result in warm frontal development over our region, with at least one...and possibly multiple excursions of moisture and lift into the forecast area next week. Global model guidance is coming into somewhat better agreement in timing one such excursion during the Mon night/Tue time frame, and this is when the highest PoPs (likely mountains/chance elsewhere) will be advertised during the period. With uncertainty increasing thereafter...and the likelihood that the baroclinic zone and moisture will be lingering in or near the CWA, at least small PoPs are maintained through the end of the period. Considerable cloud cover/elevated moisture is expected to yield relatively small diurnal temperature ranges through the period, with max temps generally expected to fall within a few degrees either side of climo, and min temps forecast to be at least 5 degrees above normal through the period.