Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sun Jun 25 2023 16:32:46 ACUS01 KWNS 251632 SWODY1 SPC AC 251630 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Sun Jun 25 2023 Valid 251630Z - 261200Z ....THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS PARTS OF THE MIDWEST/CENTRAL OH VALLEY TO THE MID/DEEP SOUTH... ....SUMMARY... Scattered to numerous severe storms are expected through tonight across a broad portion of the Midwest/Ohio Valley into the Mid and Deep South. The greatest threat for tornadoes, at least a couple of which could be strong, appears to be in the eastern Indiana, western Ohio, and northern Kentucky vicinity during the late afternoon to early evening. ....Central Great Lakes/OH Valley to the Mid/Deep South... Shortwave trough over the Upper MS Valley will shift east into Lower MI tonight. Attendant surface cyclone will similarly track east from west-central WI into west-central Lower MI. Arcing cold front will have greater eastward advancement across parts of the Midwest, with trailing portion drifting south-southeast across the Mid-South. A broad swath of severe potential remains evident ahead of this front, likely yielding scattered areas of severe storms and embedded mesoscale corridors of more numerous reports. Ongoing convection persists across southeast KY into middle/eastern TN and will probably continue along the gradually eastward-shifting, north/south-oriented MLCAPE gradient. An isolated damaging wind threat should exist downstream across the southern Appalachians. A scattered wind/hail threat may emerge within multicell clusters that can regenerate westward later this afternoon over the TN Valley and persist into this evening. Potential for more numerous severe events appears to be focused within two bimodal corridors along/ahead of the front. The first is in the vicinity of eastern IN/western OH/northern KY border. Scattered thunderstorms will increase during the next few hours in the Lake MI vicinity arcing south across IN and then southwest across the Lower OH Valley. In the wake of the morning convection in KY, trailing outflow appears to have finally stalled across western KY and far southwest IN. How far to the northeast recovery can occur in its wake is uncertain, but it is plausible that it may be able to reach the IN/OH/KY border area by late afternoon/early evening. With a plume of mid 70s surface dew points to the west of this outflow, large buoyancy with MLCAPE of 3000-3500 J/kg will become common. Despite gradual weakening of the strong mid-level jetlet attendant to the shortwave trough, the leading edge of 50+ kt 500-mb westerlies should overlay the Lower OH Valley portion of the front. This setup will likely yield the best CAPE/shear/SRH parameter space near the IN/OH/KY border area where a few intense supercells are expected, capable of producing strong tornadoes and destructive hail/wind. Quicker upscale growth into clusters/QLCS is expected with northern extent where deep-layer wind profiles will be less favorable for maintaining discrete supercell structures. This activity should eventually outpace/become pinched off from the large buoyancy plume emanating from the Lower OH Valley. A second area of potentially destructive hail and wind should emanate along the AR portion of the front. The 12Z LZK sounding had a very favorable thermodynamic profile with a mean-mixing ratio of 18 g/kg and mid-level lapse rates of 8-8.5 C/km. With 74-77 F surface dew points common to the south of the front, very large buoyancy of 3500-4000 J/kg will be prevalent by late afternoon. Scattered thunderstorms will develop across northern AR and quickly become supercells within the gradient of mid/upper west-northwesterly flow. This type of orientation semi-parallel to the front should support upscale growth during the evening. Most morning CAMs are consistent in suggesting an MCS will evolve southeast across the Lower MS Valley with an enhanced threat for damaging winds. ...Grams/Squitieri.. 06/25/2023 $$ = = = 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) .