Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Mon Oct 23 2023 16:32:02 ACUS01 KWNS 231631 SWODY1 SPC AC 231630 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Mon Oct 23 2023 Valid 231630Z - 241200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHWEST TEXAS AND THE UPPER MISSISSIPPI VALLEY... ....SUMMARY... A brief tornado is possible across a portion of southwest Texas this evening into the overnight. Isolated large hail will be possible late tonight across parts of the Upper Mississippi Valley. ....Texas Big Bend/Edwards Plateau... Low-level moisture will gradually increase across the region through tonight, while a cirrus canopy, related to the remnants of Norma, will tend to persist across a sizable part of Texas. Weak buoyancy is expected to develop and episodic bouts of isolated to scattered thunderstorms will focus from the Big Bend north-northeastward across the western Edwards Plateau, mainly this evening into the overnight. A strengthening low-level jet during this time frame will enlarge hodographs and may be sufficient for a transient supercell or two. But weak lapse rates through much of the vertical column will likely mitigate a threat beyond a low probability for a brief/weak tornado. ....Upper Mississippi Valley... Post-shortwave trough ridging and limited moisture should keep thunderstorm potential/coverage relatively low much of the afternoon and early evening. Elevated thunderstorms are expected to become more prevalent late this evening into the overnight to the north of a warm front, as a southwesterly low-level jet strengthens across Nebraska/Kansas/Iowa. Ample elevated buoyancy and steep mid-level lapse rates will favor potential for isolated large hail, spanning parts of southern Minnesota/possibly far northern Iowa eastward across Wisconsin toward the Lake Michigan vicinity. However, modest effective shear should tend to yield multicellular clustering, likely mitigating a more substantial/longer duration severe hail threat. ...Guyer/Weinman.. 10/23/2023 $$ = = = 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) .