Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Mon Oct 23 2023 17:32:33 ACUS02 KWNS 231732 SWODY2 SPC AC 231730 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Mon Oct 23 2023 Valid 241200Z - 251200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF SOUTHERN NEW MEXICO INTO WEST TEXAS...AND PORTIONS OF THE UPPER MIDWEST/GREAT LAKES... ....SUMMARY... Isolated severe thunderstorms appear possible Tuesday across parts of the Southwest into the southern High Plains, and over portions of the Upper Midwest and Great Lakes. Severe hail and strong/gusty winds should be the main threats. ....Southwest into the Southern High Plains... A southern-stream upper trough/low will continue moving slowly eastward through Tuesday night across northern Mexico, parts of the Southwest, and the southern High Plains. Primary surface low should remain over the central High Plains during the day, with a weak surface trough/dryline feature extending southward from this low across the southern High Plains. While this dryline is expected to mix slowly eastward through the day, it should return westward Tuesday evening/night over portions of west TX and far eastern NM. Generally low to mid 60s surface dewpoints should be present east of the dryline. Large-scale ascent preceding the upper trough/low will overspread parts of southern NM into west TX by late Tuesday afternoon, with convective development expected to commence shortly thereafter. Initially high-based thunderstorms that develop over the higher terrain of northern Mexico and southern NM should eventually encounter greater low-level moisture as they move eastward into west TX Tuesday evening/night. Gradually strengthening mid-level flow and related deep-layer shear will support organized updrafts, including the potential for a couple of supercells. Isolated severe hail should be the main threat with the more discrete activity, with sufficient MLCAPE to support surface-based thunderstorms expected. With time, convection should tend to grow upscale into one or more clusters as a south-southeasterly low-level jet strengthens over the southern High Plains. Strong to locally severe wind gusts may occur Tuesday evening/night with these clusters as they move east-northeastward across parts of west TX, even though the boundary-layer may tend to stabilize somewhat with the onset of nocturnal cooling. The Marginal Risk has been expanded to include more of southern NM and west TX to encompass where robust convection appears possible. But, confidence in a more concentrated corridor of severe hail/wind potential remains too low to include greater severe probabilities at this time. ....Upper Midwest/Great Lakes... Elevated thunderstorms will probably be ongoing Tuesday morning across parts of the Upper Midwest/Great Lakes. Low-level warm advection will aid maintenance of this convection through the morning, with some chance for hail with the strongest cores given ample MUCAPE forecast. In the wake of this morning activity, it remains unclear how much additional convection will develop along/near a front, as large-scale ascent appears rather nebulous. Still, the northward transport of upper 50s to low 60s surface dewpoints and the presence of steepened mid-level lapse rates should aid in the development of weak instability as modest daytime heating occurs. Amid strong deep-layer shear, any convection that can develop along/near the front through the afternoon and early evening may be capable of producing marginally severe hail and perhaps strong/gusty winds. The overall intensity of strong to severe thunderstorms should remain fairly limited owing to the weak instability forecast. Based on latest guidance, have expanded the Marginal Risk eastward to include parts of the Upper Great Lakes and vicinity. ...Gleason.. 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) .