Forecast Discussion
Summary
SYNOPSIS
... Dry high pressure will remain in place through the majority of the workweek. A cold front will push across the area Friday night or Saturday, bringing a chance of rain for portions of the forecast area. Temperatures will remain above normal ahead of the front, becoming below normal this weekend behind the front.
NEAR TERM /THROUGH TUESDAY/... As of 1025 PM EDT Monday: A general quiet forecast continues as a potent upper ridge remains in place over the Gulf Coast / Mississippi Valley, and a surface high circulating over the upper Ohio Valley. Sustained dry northeasterly flow continues at the low levels, maintaining stable conditions with a subsidence inversion in place.
Tonight, model fields depict a slightly more easterly component to winds; however, the amount of moisture trapped under the subsidence inversion is lower than the past few days. In fact, skies have now cleared which hasn't been the case at this time during the past few evenings. With fog already forming in the Little TN Valley, expect the valley fog to be widespread with only some stratocu to perhaps limit coverage. Lows still look to remain a category or more above normal.
Tomorrow, more of the same. Dry northeast flow will continue on the southeastern limb of the surface high over New England...allowing dry and mostly sunny conditions to continue. There will be some fair weather cumulus again with coverage similar to Monday. Temperatures to remain a category or so above normal amid mostly sunny skies and excellent insolation.
SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/... As of 155 pm EDT Monday: Blocking pattern will gradually break down/shift east through the short term, with the axis of a major upper trough expected to be centered in the vicinity of the MS Valley through the end of the period, and upper ridge gradually relinquishing its grip on the East Coast. In the interim, the warm and dry conditions will persist across the western Carolinas and northeast GA. Min temps will remain a category or so above climo, with maxes expected to be around 5 degrees above normal.
LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... As of 205 pm EDT Monday: Heights continue to fall across the East during the early part of the extended period, with anomalous/deep upper trough expected to set up across the region by mid-way through the weekend. Associated frontal boundary is expected to sweep through our forecast area on Saturday. There remains considerable uncertainty regarding the details of the orientation of any short wave details, and therefore with the timing of the front...and with how much forcing for UVV will be available this far south. However, even the global model guidance that is farther south with its forcing (e.g., the ECMWF) are rather stingy with any QPF response, but most guidance sources feature rather spotty QPF, and we generally limit PoPs to only a slight chance Fri night through Sat. After one more quite warm day on Friday, a transitional day is expected to yield max temps near climo on Saturday. The rest of the extended will feature temps a good 5-10 degrees below normal.