Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Jun 13 2023 05:13:42 ACUS02 KWNS 130513 SWODY2 SPC AC 130512 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1212 AM CDT Tue Jun 13 2023 Valid 141200Z - 151200Z ....THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS LATE WEDNESDAY AFTERNOON AND EVENING ACROSS PARTS OF NORTHEASTERN LOUISIANA AND ADJACENT SOUTHEASTERN ARKANSAS...CENTRAL MISSISSIPPI...CENTRAL/SOUTHERN ALABAMA...SOUTHWESTERN GEORGIA... ....SUMMARY... Thunderstorms capable of producing very large, damaging hail and severe wind gusts are possible across portions of the Gulf Coast states Wednesday. ....Synopsis... Models continue to indicate that short wave developments will become a bit more progressive into and through this forecast period. One initially prominent embedded mid-level low may begin to weaken more substantively by Wednesday, while redeveloping east of the lower Great Lake through the Northeast, accompanied by a modest surface cyclone. Broadly cyclonic flow around the southern periphery of the mid-level low may generally remain in phase with broad troughing in a separate branch of westerlies, across the lower Mississippi Valley into the western Atlantic. A series of smaller-scale perturbations emerging from the Intermountain West are forecast to continue accelerating within broadly confluent flow into and through this regime, maintaining seasonably strong mid-level flow across much of the Southeast. This may include 40-70 kt westerly/west-northwesterly winds in the 700-500 mb layer, while in lower levels (around 850 mb), winds weaken some as the stronger flow begins to shift off the Atlantic Coast. At the same time, higher moisture content air will remain mostly confined to areas along and south of a remnant surface front/conglomerate convective outflow boundary across the eastern Gulf Coast states into parts of the southern and central Great Plains. It still appears that this moisture will be overspread by warming elevated mixed-layer air, and perhaps weak cooling farther aloft, contributing to increasing convective instability from Tuesday into Wednesday. ....Gulf Coast states... Lower predictability associated with the smaller-scale perturbations progressing through the flow, and the unknown influence of the still uncertain convective evolution during the preceding day, remain complicating factors concerning convective potential for Wednesday through Wednesday night. Widely scattered convection capable of producing severe hail and wind may be ongoing at the outset of the period along the frontal zone, and continue into the day Wednesday. However, there does appear a consistent signal among the various model output that a zone of stronger differential surface heating may develop by late afternoon, roughly from the Arkansas/Louisiana border vicinity through central Mississippi and Alabama into southwestern Georgia. This may become a focus for increasing, initially discrete storms, in the presence of strong deep-layer shear supportive of supercell structures. Given forecast thermodynamic profiles including steep mid-level lapse rates and large CAPE, the environment appears conducive to the development of very large, damaging hail in the strongest storms. Damaging wind gusts are also likely, particularly as activity tends to grow upscale along this corridor into Wednesday evening. ...Kerr.. 06/13/2023 $$ = = = 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) .