Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Mon May 29 2023 12:49:44 ACUS01 KWNS 291249 SWODY1 SPC AC 291247 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0747 AM CDT Mon May 29 2023 Valid 291300Z - 301200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON/EVENING FROM THE CENTRAL HIGH PLAINS TO EASTERN SD... ....SUMMARY... Isolated strong to severe thunderstorms capable of producing hail and damaging winds will be possible this afternoon and evening in parts of the central High Plains into Nebraska and South Dakota. ....Central/northern Plains this afternoon/evening... The large-scale pattern has been very slow to change for the past several days, with a Rex block persisting from the Great Lakes into the Southeast, upstream troughing over the northern Plains and ridging over the southern Rockies (downstream from a closed low near the CA coast). In this relatively weak flow regime, only weak surface lee troughing is expected from the southern/central High Plains into the northern Plains, with a continued feed of mid 50s to low 60s boundary-layer dewpoints east of the lee trough. Surface heating and steep midlevel lapse rates will support MLCAPE of 1500-2000 J/kg with minimal convective inhibition, and widely scattered thunderstorm development is expected along the lee trough and possibly the Black Hills. Vertical shear will remain rather weak (effective bulk shear 25-30 kt) and the net result will be a weakly forced environment favoring primarily multicell clusters, and perhaps a marginal supercell or two. Isolated large hail of 1-1.75 inches in diameter and severe outflow gusts of 60-70 mph will be possible from mid-late afternoon into this evening. ....Southern Plains today... With rising heights over NM today, a series of MCVs have finally moved east of the southern High Plains. Convective clusters will be possible today from southeast KS into central TX in association with the remnant MCVs. Some modestly enhanced midlevel westerly flow has been observed with the MCV along the northern OK/southern KS border per the KVNX VWP. However, the steeper lapse rates will remain farther west and vertical shear will generally remain weak, which both suggest that severe storms are unlikely. ...Thompson/Broyles.. 05/29/2023 $$ = = = 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) .