... Dry and cool high pressure will continue to build over the region through the weekend. A vigorous low pressure system will move through the Plains on Monday and the Ohio River valley Tuesday spreading moisture back across the Southeast. Conditions will remain unsettled through the middle of next week.
NEAR TERM /THROUGH TODAY/... As of 1245 am Saturday...temps continue to slowly fall as we move into the overnight with winds now calm over much of the CWFA. Under clear skies, we can expect good radiational cooling thru the early morning. Fog potential remains minimal as low dewpts will keep RH values from getting too high.
Otherwise, the center of a large high pressure system will migrate across the Tennessee Valley tonight to the Carolina Coastal Plain by Saturday aftn. This should result in clear skies and light winds for the bulk of the near term. Latest visible imagery shows the snow cover continuing to melt, with only high elevations showing much left. So I don't plan to issue another SPS for black ice for tonight. Cannot rule out a slick spot or two in the mountain valleys, and patchy black ice possible above 3500 ft. Temps will fall into the teens to around 20 in the mountains, and lower to upper 20s across the Piedmont, about 7-10 deg below normal. Temps rebound nicely on Saturday, with highs in the 50s (about a category below normal).
SHORT TERM /TONIGHT THROUGH MONDAY/... As of 145 PM EST Friday: The short term starts dry with surface high pressure still in place over the southeastern CONUS. An upper level wave will eject from the Four Corners region, however, generating a surface low across the Great Plains. At the surface, high pressure will move off the east coast and moisture will feed back into the area from the Gulf beginning later on Sunday. A frontal zone will activate across the OH River Valley Sunday evening, extending into the Carolinas by Sunday night and increasing rain chances by the late evening. Some of the mountain peaks may be cold enough for some snow at onset, but everyone should change over to rain fast enough that impacts from winter weather are not expected. Rain will continue to spread over the area Tuesday as the upper low and surface cold front approach the Carolinas and increase forcing substantially. The front will be progressive, but with decent forcing and moisture, a quick 1-2" of rainfall is possible before the cold front moves out of the area late Monday. Max temps Sunday will be above average ahead of the front moving in, but cloud cover overnight will keep overnight lows about 10 degrees above normal. Persistent cloud cover and rainfall will keep maxes Monday to about average.
LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... As of 215 PM EST Friday: On the heels of the front Monday night and after a relatively quiet day on Tuesday, some moisture will likely wrap around the back of the low pressure system, and another secondary low seems to be generating along a remnant frontal boundary and moving quickly across the Great Lakes region, giving mostly the mountains another quick shot at some precip and maybe even a rain/snow mix in the high terrain Wednesday night. This won't be a classic NW flow precip/snow event due to the formation of the secondary low, but the result seems to be largely the same. Some moisture may break containment from the mountains Wednesday night, and with a large upper trough digging into the southeastern CONUS, there may be enough forcing to generate some light showers outside the mountains - pops were only kept in the slight chance to chance range to account for this. Some NW flow moisture may linger through Thursday, but the influence of surface high pressure should arrive back in the area next weekend. There is some uncertainty about the possibility of more moisture returning on Saturday as the upper trough sharpens and moves over the Carolinas, but this part of the forecast remains low in certainty at this time. Upper troughing will keep temps for most of the medium range a few degrees below climo.