... Weak high pressure remains over the area today. A weak cold front drops south across the area Saturday night which brings our next chance for rain, and then a brief cool down Sunday. Another cold front will arrive from the north on Tuesday or Wednesday.
NEAR TERM /THROUGH SATURDAY/... As of 958 PM EDT Friday: Unperturbed weather continues with generally clear skies across the region. No major changes were warranted late this evening, with the forecast on track going into tonight.
Relatively benign and quiet weather will persist across the region through Saturday as we remain in the nebulous part of the upper pattern stuck between the upper anticyclone building over the nrn Plains/upper Midwest/wrn Ontario and the circulation associated with the newly-named TS Arlene in the eastern Gulf and an upper trof to its north. Thus, we remain bereft as far as mid/upper forcing is concerned. For tonight, some mtn valley fog will be possible once again, but otherwise fair with low temps close to normal. For Saturday, temps should creep up another category warmer compared to today. In the afternoon, we will watch for a backdoor cold front to approach from the N/NE. Guidance indicates the development of some deep convection ahead of the boundary along/N of I-40 in the late afternoon, which seems reasonable enough to ramp up a chance of precip by the end of the day. Buoyancy looks modest at best, so thunderstorms that develop are not likely to become severe.
SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/... As of 220 PM Friday: A large omega blocking pattern remains over the CONUS through the short term fcst period. At the sfc, a backdoor cold front will track towards the Carolinas and northeast Georgia Saturday evening before tracking across the region Saturday night into late Sunday afternoon. CAMs show shower and thunderstorm chances increasing ahead of the front Saturday evening into Saturday night, with a lull looking plausible on Sunday morning as drier air filters into the region behind the front. Have the highest PoPs confined to the NC Piedmont with lower PoPs elsewhere per CAM trends. Model soundings show the potential for locally heavy rainfall Saturday night with these showers and thunderstorms thanks to PWATs ranging from 1.3-1.5 inches and low wind shear values leading to slow storm motion. Lows Saturday night will be a few degrees above climo. Diurnal shower and thunderstorm chances return Sunday afternoon and early evening along the front as it sinks southward across the CWA. Highs on Sunday will be around 3-7 degrees below climo thanks to the cooler airmass behind the front. Lows Sunday night will be near to a few degrees below climo. Sfc high pressure builds in behind the departing backdoor front on Sunday night into Monday. Global models continue to show diurnal convection developing across the higher terrain Monday afternoon and evening, so have the highest PoPs confined to the mtn zones. Highs Monday afternoon will rebound to a few degrees above climo. The overall severe threat each day looks to be low, although cannot entirely rule out the potential for isolated damaging wind gusts with any storm that manages to become strong to severe.
LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... As of 240 PM Friday: The omega blocking pattern remains in place over the CONUS through the long term fcst period while gradually retrograding middle to late next week. A large area of low pressure will push southward from eastern Canada into the Mid-Atlantic Monday evening into Wednesday. This will act to pull a sfc cold front into the Carolinas Tuesday into Wednesday, increasing shower and thunderstorm chances. Capped PoPs to chance on Tuesday and Wednesday as models are not in great agreement regarding how much moisture will be present across the region. The cold front could stall just south of the CWA Thursday into Friday, which could act to keep shower and thunderstorm chances around for the extreme southern tier of the fcst area. Went with a slight chance PoP on Thursday and dry conditions on Friday due to model disagreement regarding the overall sfc pattern. Temps Tuesday into Tuesday night will be a few degrees above climo before dropping to a few degrees below climo the rest of the fcst period.