Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Apr 19 2023 17:32:36 ACUS02 KWNS 191732 SWODY2 SPC AC 191730 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Wed Apr 19 2023 Valid 201200Z - 211200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS PARTS OF THE MIDDLE MISSISSIPPI VALLEY INTO THE ARKLATEX AND CENTRAL TEXAS... ....SUMMARY... Widely scattered severe thunderstorms capable of hail and severe gusts are possible from parts of mid Mississippi Valley southwestward into the Ark-La-Tex and central Texas Thursday afternoon and Thursday night. ....Synopsis... A mid-level low will migrate slowly eastward across the Upper Midwest with a larger-scale trough longitudinally located over the Great Plains. An embedded disturbance/mid-level speed max will quickly move from KS/NE Thursday morning to WI by early evening. In the low levels, a surface low will develop northeastward from IA into the Upper Great Lakes and occlude, while a trailing cold front will push east/southeast across the mid MS Valley into the southern Great Plains. ....Ozarks/Ark-La-Tex/Southern Plains... A cold front will bisect OK and extend north-northeastward into eastern KS/western MO during the morning and continue east-southeast through peak heating. A reservoir of adequately rich low-level moisture --characterized by mid-upper 60s dewpoints-- will reside across the Ozarks southward into north TX. Strong heating will contribute to a moderate to very unstable airmass by early-mid afternoon. MLCAPE is forecast to range from near 1000 J/kg over southern MO to 3500 J/kg over central TX. As the cap weakens near the front during peak heating, scattered thunderstorms are forecast to develop. Moderate to strong deep-layer shear will promote storm organization. Supercells capable of large to very large hail will be possible from north TX southward along the I-35 corridor into central TX. Additional storm development is likely during the evening with upscale growth in one or more bands of storms likely during the evening into the overnight. The severe risk will likely lessen as storms move east nearing the MS River and moving towards the Gulf Coast late. ....Mid MS Valley and WI... At the start of the Day-2 period, a 60-kt LLJ will be located over the lower MO Valley. This feature's associated warm-air advection will promote scattered showers/thunderstorms during the morning across northern MO into the eastern half of IA and parts of adjacent IL/WI during the morning. Elevated buoyancy amidst strong shear will lend a conditional risk for strong and locally severe thunderstorms. Isolated large hail and perhaps damaging gusts may accompany this activity. It remains a bit uncertain whether this early day thunderstorm activity will continue and/or additional storms will redevelop via cloud breaks/heating during the midday into the afternoon, especially with north extent. Nonetheless, it seems a severe risk may develop during the afternoon and perhaps linger into the evening with a broken band of storms from the mid MS Valley northward into WI. If greater destabilization can occur from IL into southern WI, a focused threat for damaging gusts and perhaps a tornado or two could materialize Thursday afternoon/early evening. Uncertainty is high regarding this scenario and will defer this possibility to later outlooks. ...Smith.. 04/19/2023 $$ = = = 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) .