Subj : DAY2SVR: Nws Storm Predic To : All From : Mike Powell Date : Thu Jan 11 2024 08:53:00 ACUS02 KWNS 110607 SWODY2 SPC AC 110605 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1205 AM CST Thu Jan 11 2024 Valid 121200Z - 131200Z ....THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FRIDAY AFTERNOON AND INTO FRIDAY EVENING ACROSS PARTS OF EAST CENTRAL AND SOUTHEASTERN ALABAMA...MUCH OF CENTRAL GEORGIA AND SOUTH CAROLINA INTO SOUTHERN NORTH CAROLINA... ....SUMMARY... Severe thunderstorms, with potential to produce high winds and a few strong tornadoes, are possible across parts of the Southeast Friday through Friday evening. ....Discussion... There appears little substantive change in the latest available ECENS/ECMWF and GEFS concerning the forecast evolution for this period. Strong surface cyclogenesis is likely to proceed Friday across the Mississippi Valley through Atlantic Seaboard, as a vigorous supporting short wave trough pivots northeast of the southern Great Plains. It still appears that the center of the growing cyclone will undergo a period of rapid deepening across the lower Ohio Valley during the day, including minimum surface pressures falling on the order of 15-20 mb in a 12 hour period, though the 00Z NAM/03Z RAP take a track to the northwest of the other guidance into the Great Lakes region through late Friday night. Regardless, associated strengthening of deep-layer wind fields probably will including a developing swath of 90-120+ kt cyclonic/southwesterly flow at 500 mb across the lower Mississippi Valley, through portions of the Northeast and Mid Atlantic by the end of the period. In the 850-700 mb layer, 50-90 kt south to southwesterly flow is generally forecast to overspread the inland advancing warm sector. There remains some uncertainty concerning just how expansive of an unstable warm sector may develop, with perhaps low-level warming and moistening becoming sufficient, in the presence of strong forcing for ascent, for weak boundary-layer destabilization northeast of the lower Mississippi Valley through parts of the Tennessee and lower Ohio Valleys during the day. More substantive low-level moistening is probable off the north central/northeastern Gulf of Mexico, into the eastern Gulf through south Atlantic coast states. However, with the mid-level cold pool forecast to shift north of this region, relatively warm layers aloft, even in advance of mid-level subsidence warming nosing east-northeastward across coastal areas, could inhibit destabilization. More problematic, concerning the severe weather potential, the NAM and Rapid Refresh forecast soundings are slow to erode the initially cool boundary layer, and maintain at least a shallow near surface stable layer. If this verifies, convective potential will probably be mitigated. However, a corridor of strong surface pressure falls still appears likely to develop across the Southeastern Piedmont, from Alabama through the Carolinas midday Friday through Friday evening, near the southern periphery of the mid-level height falls. Associated forcing may contribute to more rapid modification of the boundary-layer, in the presence of an environment otherwise becoming conditionally supportive of significant severe weather potential. Strong to severe thunderstorm development, initiating Thursday night across the southeastern Great Plains into the lower Mississippi Valley, may be ongoing at the outset of the period, spreading east-northeast of the Mississippi River Friday morning, before perhaps weakening. Renewed thunderstorm intensification is then expected near/ahead of a developing pre-frontal dryline structure developing across east central/southeastern Alabama by early afternoon, particularly near where it intersects a strengthening frontal zone across the Piedmont. This probably will be maintained while spreading east-northeastward across Georgia into the Carolinas by late Friday evening. Although the evolution of an organized convective cluster still appears possible, discrete supercell development may remain the primary convective mode, accompanied by a risk for strong tornadoes. ...Kerr.. 01/11/2024 $$ --- SBBSecho 3.14-Linux * Origin: Ilink: CCO - capitolcityonline.net (454:1/105) .