... A weak cold front will stall across the Gulf Coast Friday. High pressure builds into the region this weekend. Early next week another frontal system will bring better rain chances to the area.
NEAR TERM /THROUGH FRIDAY/... As of 935 PM: The region remains under a fast quasi-zonal flow aloft. Copious cirrus remains over the area while low clouds have diminished. A southern-stream wave moves by overnight; however, guidance continues to show little precip for all but the Lakelands area. Even there, QPF would be very light. Low temps will remain above normal, and more importantly well above freezing where precip is plausible. The clouds should keep fog to a minimum, mainly in the Little TN basin. Upper flow will diminish during the day Friday as a sfc high spreads in from the mid-Mississippi Valley, and the cirrus should begin to thin or advect out. Increasing sunshine will allow max temps to rise back into the mid to upper 50s across the lower mtn valleys and NW NC Piedmont, and closer to 60 across the remainder of the Piedmont. Dewpoints will mix out such that RH will drop to 25-30 percent across some of the area, enhancing fire danger slightly, but winds will be light.
SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/... As of 300 PM Thursday: Zonal flow Friday evening will transition into broad weak ridging throughout the day on Saturday as a high pressure system located near the Great Lakes Region builds into the southeastern United States. This will lead to dry conditions and plenty of sunshine along with temps near or just below normal. Saturday night minimal cloud cover will lead to good radiational cooling allowing temps to drop into the mid to low 20s in the foothills and higher elevations, and upper 20s and low 30s elsewhere, a few degrees below normal for this time of year. Sunday morning high pressure should be centered over the Carolinas. However, this high pressure system should track offshore Sunday afternoon into Sunday evening as a low pressure system develops across the Southern Plains. The warm front associated with this low pressure system will lift north over the southeastern United States Sunday afternoon into Sunday night increasing rain chances for the CWA.
LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... As of 2:30pm EST Thursday: Weather activity will pick-up in the extended with 2 southern upper synoptic systems moving through: the first on Monday, and the second on Wednesday or Thursday. Both of these systems will be on the warm side for this time of year, with precipitation currently looking to be all rain in all parts of the CWA, with the possible exception of a little snow on Wednesday at the higher elevations in North Carolina.
For the first system, the only real differences between GFS and EC models is that the EC weakens the ridge late on Sunday with some small shortwaves and brings some light precipitation into the area prior to the main front later on Monday. For the second system, GFS and EC differ considerably on timing, with the EC nearly a day behind the GFS, not bringing in the second round until Thursday.
FROPA with the first system concurrently looks to be around Monday night, with southwesterly warm and moist advection ahead of it, followed by dry northwesterly advection on Tuesday. Winds continue to veer to northeastward Tuesday evening, creating cold-air-damming (CAD) conditions that look to last through the next system passage Wednesday or Thursday. CAD on Wednesday should preclude the possibility of thunder for the second system, but there is an outside chance for a little thunder late on Monday with some showers that move into the CWA from the west where GFS predicts a small amount of SBCAPE. FROPA should occur behind the second system late on Wednesday or Thursday.
Due to southern track of these 2 systems and consequent southerly flow at times, temperatures will be generally above normal Monday and Tuesday, with CAD creating cloudy and mild conditions on Wednesday.