Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Jul 11 2023 05:58:10 ACUS02 KWNS 110558 SWODY2 SPC AC 110556 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1256 AM CDT Tue Jul 11 2023 Valid 121200Z - 131200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR MUCH OF MISSOURI/ILLINOIS INTO ADJACENT PORTIONS OF SOUTHEAST NE...EASTERN KS...SOUTHERN IA...AND WESTERN KY/IN... ....SUMMARY... Strong/severe storms will be possible across much of Missouri and Illinois and adjacent portions of the central Plains and Midwest on Wednesday. ....Synopsis... A seasonably deep upper-level cyclone is forecast to remain centered somewhere near Hudson Bay on Wednesday, with an attendant trough extending southward into parts of the central/eastern CONUS. Meanwhile, an upper ridge will persist over the Southwest and southern Rockies. Between the southwestern ridge and eastern trough, a belt of moderate midlevel northwesterly flow will remain in place from the central/northern Plains into parts of the Midwest/mid-upper MS Valley and Great Lakes. ....East-central Great Plains into the Mid MS Valley and Midwest... Severe thunderstorms will again be possible across parts of the central Plains into the mid MS Valley and Midwest, within a favorable northwesterly flow regime. The typical uncertainties remain regarding the impact of antecedent convection on the most favored corridor and timing for potential MCS development. One or more storm clusters/remnant MCSs will likely be ongoing Wednesday morning somewhere from the lower MO Valley into the mid MS Valley. It remains uncertain as to whether morning convection will reintensify and move southeastward, or if new diurnal storms will develop during the afternoon and grow upscale Wednesday evening, or if some combination of these scenarios will evolve. Regardless, the most favored corridor for severe thunderstorms is expected from eastern parts of the central Great Plains into the mid MS Valley. With moderate to strong instability and sufficient deep-layer shear, any diurnal development along the convectively reinforced front may evolve into a few supercells, with an attendant threat of large hail, localized severe gusts, and possibly a tornado. Otherwise, a tendency toward upscale growth is expected, with a potentially more concentrated swath of severe gusts possible with any mature MCS that can evolve during the afternoon and/or evening. A 10%/hatched significant wind area has been added where the forecast pattern and recent guidance suggest the greatest relative risk of a severe-wind producing MCS, though uncertainty remains too high for more than 15% unconditional severe-wind probabilities. ....Upper Great Lakes into New England... A shortwave embedded within the longwave trough is forecast to move across parts of southern Quebec and northern Maine on Wednesday, as a cold front moves southeastward into parts of the upper Great Lakes and New England. Scattered thunderstorms will be possible along/ahead of the front during the afternoon and evening. Weak to moderate buoyancy and modest deep-layer shear will support a threat of locally damaging gusts with the strongest cells/clusters. ...Dean.. 07/11/2023 $$ = = = 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) .