Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Jan 24 2023 06:00:49 ACUS02 KWNS 240600 SWODY2 SPC AC 240559 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1159 PM CST Mon Jan 23 2023 Valid 251200Z - 261200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS WEDNESDAY INTO WEDNESDAY EVENING ACROSS PARTS OF SOUTHEASTERN ALABAMA...NORTHERN FLORIDA...SOUTHERN AND CENTRAL GEORGIA...CENTRAL AND EASTERN NORTH CAROLINA...EASTERN NORTH CAROLINA AND SOUTHEASTERN VIRGINIA... ....SUMMARY... A risk for damaging winds and a few tornadoes will accompany showers and thunderstorms overspreading much of the southern Atlantic Coast states Wednesday into Wednesday evening. ....Synopsis... While a mid-level subtropical high maintains strength across the Caribbean/Bahamas vicinity, a deep mid-level low of Arctic origins may continue to redevelop southwestward toward the Hudson Bay vicinity during this period, as a vigorous short wave impulse digs around its western through southern periphery. At the same time, within persistent large-scale eastern Pacific riding, another prominent mid-level high is forecast to form, at higher latitudes than the preceding one, to the west of the northern U.S. Pacific coast. Downstream of this regime, a couple of digging impulses will maintain mid-level troughing across the Four Corners states, while a much more vigorous perturbation, initially over the Mid South vicinity, continues accelerating east-northeastward. As the lead perturbation approaches the lower Great Lakes/Mid Atlantic Wednesday through Wednesday night, it may gradually become absorbed within larger-scale troughing evolving to the south of the Arctic low. An initial associated surface cyclone is forecast to continue to deepen across the upper Ohio Valley into lower Great Lakes, while secondary cyclogenesis commences from the lee of the southern Appalachians through the northern Mid Atlantic and southern New England coasts by 12Z Thursday. It still appears that there will be coinciding substantive further intensification of a west-southwesterly mid/upper jet, including speeds of 100-120 kt around 500 mb, across the eastern Gulf through southern/middle Atlantic Coast states and southern New England. A 50-70+ kt south-southwesterly jet around 850 mb likely will shift through Georgia and the Carolinas through midday Wednesday, before continue to propagate across the middle and northern Atlantic coast through the remainder of the period. ....South Atlantic Seaboard... Within the evolving warm sector of the cyclone, it appears that boundary-layer moisture characterized by dew points in excess of 60F will overspread much of the southern through middle Atlantic Seaboard, in the presence of the intense deep-layer mean wind fields and vertical shear. It still appears that lower/mid-tropospheric lapse rates will remain generally weak. However, aided by an initially better influx of moisture return off the Gulf of Mexico, a pre-frontal squall line (expected to be ongoing early Wednesday) may maintain a risk for damaging winds and tornadoes across at least southeastern Alabama, central/southern Georgia, and the remainder of the Florida Panhandle into parts of northern Florida. Thereafter, perhaps after a period of diminishing convective trends, increasing mid/upper forcing for ascent may support a gradual intensification of convection in a pre-cold frontal band across parts of the Carolina Piedmont into the southern Mid Atlantic coast. It is not entirely clear how much of this activity will be capable of producing lightning due to relatively warm mid-levels. However, a number of models are now increasingly suggestive that initially stable near-surface lapse rates may trend neutral to weakly unstable prior to the arrival of this activity. Given the size of the forecast low-level hodographs, including modest clockwise curvature and mean speeds in excess of 50 kt in the lowest couple of kilometers above ground level, the environment may become conducive to damaging gusts reaching the surface, and a risk for tornadoes. The potential for tornadoes could increase as the convection and associated forcing for ascent encounter increasingly moist low-level inflow off the Atlantic, which may support intensifying convection, including supercells, across the North Carolina coast/Outer Banks region Wednesday evening. ...Kerr.. 01/24/2023 $$ = = = To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM. --- SBBSecho 3.14-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .