Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Fri Jun 30 2023 06:02:15 ACUS01 KWNS 300602 SWODY1 SPC AC 300600 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Fri Jun 30 2023 Valid 301200Z - 011200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL HIGH PLAINS EASTWARD INTO PARTS OF THE MS/OH/TN VALLEYS... ....SUMMARY... Severe storms producing wind damage and isolated hail are expected today mainly from Missouri and Illinois southeastward toward the southern Appalachians. Severe storms with large hail and severe wind are also possible over the central and southern High Plains. ....Southern IA/Northern MO into parts of the OH/MS/TN Valleys... Another round of severe thunderstorms is possible later today along the periphery of a weakening upper ridge over the lower MS Valley, but uncertainty remains regarding the details. There is some potential for convection emanating out of KS/NE early this morning to evolve into an MCS that will move across northern MO/southern IA later this morning, and potentially into parts of the MS/OH Valleys this afternoon. However, early-morning convection across the central Plains is much less intense than at this time last night, and the immediate downstream environment is not as volatile, so the potential for a forward-propagating MCS remains uncertain. However, if the early-day convection is limited, then there will be greater potential for destabilization prior to potential storm development this afternoon and evening near the effective surface boundary. Strong buoyancy and modest but sufficient deep-layer shear could support a supercell threat across parts of the MS/OH Valleys, if an early-day MCS does not occur. Under this scenario, an upscale-growing cluster could spread into parts of the TN Valley and Southeast, with a damaging-wind threat. A separate area of elevated convection is possible farther east this morning across parts of eastern KY/TN, within a warm-advection regime. Guidance varies regarding the intensity and longevity of this convection, but some isolated hail and wind damage will be possible during the morning. Some clustering of this convection is also possible with time, which could potentially move southward into parts of AL and GA with a localized damaging wind threat. ....Central/southern High Plains and vicinity... A positively tilted upper trough is forecast to move across the southern/central High Plains later today. Moderate instability and 40+ kt of effective shear will again support supercell potential across parts of eastern CO and vicinity, with a threat of very large hail and possibly a tornado or two. With the approaching trough arriving relatively early in the day, storm coverage may become widespread, resulting in messier convective modes, but a continued threat for hail and severe gusts is expected as storms spread eastward across parts of KS/NE through the evening. Deep-layer shear will be somewhat weaker into the southern High Plains and west TX, but scattered storms capable of isolated hail and severe gusts will be possible during the afternoon and evening in this region as well. ...Dean/Weinman.. 06/30/2023 $$ = = = 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) .