Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Fri Sep 05 2025 05:40:46 ACUS01 KWNS 050540 SWODY1 SPC AC 050539 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1239 AM CDT Fri Sep 05 2025 Valid 051200Z - 061200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE BORDER AREAS OF TN/MS/AL TO WV/OH... ....SUMMARY... Scattered damaging winds, isolated severe hail, and a brief tornado or two are possible from the Upper Ohio to Tennessee Valleys during the late afternoon and evening. ....Upper OH to TN Valleys... Neutral mid-level height change and initially weak convergence along a slow-moving cold front should delay diurnal convective development. But eastward progression of a low-amplitude impulse, currently over western KS, and strengthening low-level convergence should yield scattered thunderstorms in the late afternoon to early evening. The bulk of strong mid-level flow will largely lag behind the portion of the front that is south of the Upper OH Valley. But with the late day timing of storms, an extensive plume of moderate buoyancy should be prevalent ahead of it. Several multicell clusters and transient supercell structures should develop during the evening within the moderately sheared, southwesterly flow regime. Scattered damaging winds will be the primary hazard, with isolated severe hail and a brief tornado also possible. The severe threat will diminish towards late evening given the extensive overturning and lack of stronger low-level flow/shear to sustain the threat overnight. ....North TX to Mid-South... An elongated mid-level thermal trough, characterized by 500-mb temperatures of -10 to -12 C, will extend into north TX, well to the south of a persistent vertically stacked cyclone over northern ON. Most guidance suggests low to mid-level wind fields will be modest and contain veer-back-veer signatures. Strong speed shear should be mainly confined above 500 mb, coincident with poor upper-level lapse rates atop steeper mid-level lapse rates. Consensus of CAM guidance suggests a messy convective mode should be common as convection increases in the late afternoon and evening, along the more west/east-oriented portion of the surface cold front. Given these factors, have maintained a level 1-MRGL risk for an isolated severe hail/wind threat with a southward shift based on latest guidance. ...Grams/Squitieri.. 09/05/2025 $$ = = = 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 3.28-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .