Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Apr 29 2025 06:05:34 ACUS01 KWNS 290604 SWODY1 SPC AC 290602 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0102 AM CDT Tue Apr 29 2025 Valid 291200Z - 301200Z ....THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR PARTS OF WEST TX INTO SOUTHWEST OK...AND FOR PARTS OF THE OHIO VALLEY AND LOWER GREAT LAKES... ....SUMMARY... Scattered severe thunderstorms are possible within a broad swath from the Lower Great Lakes to the southern High Plains, mainly during the afternoon to evening on Tuesday. Corridors of greater threat are expected over the Upper Ohio Valley/Lower Great Lakes and in parts of west Texas into southwest Oklahoma. ....Synopsis... A deep mid/upper-level shortwave trough will move eastward across the Great Lakes into southeast Canada today. A deepening surface low will move across Quebec during the day, as an attendant cold front moves across the Great Lakes, Ohio Valley, and Northeast. To the west, a mid/upper-level trough and embedded midlevel cyclone will move very slowly eastward across the Four Corners/Southwest. A weak surface low is expected to remain nearly stationary near the TX Trans-Pecos region. A cold front initially moving southward into the southern Plains will tend to slow down with time, with its position becoming modulated by repeated rounds of convection. ....Ohio Valley into the Lower Great Lakes... Some uncertainty remains regarding the evolution of overnight convection into the start of the D1/Tuesday period. However, most guidance suggests that, despite weakening midlevel lapse rates, moderate buoyancy will develop along/ahead of the front from the Ohio Valley into parts of the Lower Great Lakes. Any ongoing morning convection may intensify as it moves east-northeastward, with additional development expected along/ahead of the front this afternoon. Strong low/midlevel flow will support development of organized storm clusters, along with some potential for discrete or embedded supercells. Scattered damaging winds will be possible, with some potential for swaths of more concentrated wind damage if any organized clusters or linear segments develop. 35-50 kt in the 850-700 mb layer will support sufficient low-level shear for some supercell and/or line-embedded tornado threat. Isolated hail could also accompany any persistent supercell structures. ....West TX into the Ozarks... Multiple rounds of thunderstorms are expected across the southern Plains in the vicinity of the surface front, with widely scattered diurnal development also possible along the southward trailing dryline into the Permian Basin vicinity. Strong midlevel flow east of the Southwest trough will provide sufficient deep-layer shear for storm organization, within a moderate to strongly unstable environment near/south of the front. Occasional supercells will be possible, with a threat of large to very large hail, severe gusts, and a few tornadoes. One or more clusters are likely to develop and spread eastward, which could provide localized swaths of more concentrated strong/severe gusts. The favored corridor of any such clusters remains somewhat uncertain, with the front expected to gradually sag south with time. ...Dean/Weinman.. 04/29/2025 $$ = = = 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 3.20-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .