Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Fri May 26 2023 17:32:18 ACUS02 KWNS 261732 SWODY2 SPC AC 261730 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Fri May 26 2023 Valid 271200Z - 281200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN/CENTRAL PLAINS... ....SUMMARY... Isolated to scattered severe thunderstorms appear possible across much of the High Plains Saturday afternoon and evening. Large hail and strong to severe wind gusts should be the main threats, with slightly better severe potential evident over portions of the northern/central Plains. ....Synopsis... An upper trough over much of the western CONUS Saturday will advance slowly eastward towards the Rockies through the period. Multiple embedded mid-level shortwave troughs/vorticity maxima should encourage convective development along much of the length of the High Plains by Saturday afternoon. Downstream, upper ridging will persist over the Great Lakes/Northeast, while a broad, closed upper low remains centered over the Southeast. A weak surface low should gradually deepen through the day across the central High Plains, with weak lee troughing extending southward from this low across the southern High Plains. ....Northern/Central Plains... Thunderstorms should develop by early afternoon across the higher terrain of WY/MT, and gradually spread northeastward with time as an embedded shortwave trough ejects over the northern/central Plains. Once this initially high-based convection encounters greater low-level moisture and instability along/east of the lee trough, it should gradually intensify. Deep-layer shear appears somewhat marginal for organized convection, but around 25-35 kt of effective bulk shear should be enough to support a mix of multicells and transient supercells. Isolated large hail will be a threat with the more discrete convection initially, as moderate instability owing to the presence of steep mid-level lapse rates aids updraft strength. With time, one or more clusters should develop and spread northeastward through the early evening while posing some threat for severe/damaging winds. Have added a Slight Risk for hail/wind across the part of the northern/central Plains where the greatest concentration of organized convection appears possible. ....Southern Plains... Less confidence exists in overall thunderstorm coverage and intensity with southward extent along the lee trough into the southern Plains. Lingering convection and cloud debris from Friday night may still be ongoing across parts of this region at the start of the period Saturday morning, which could complicate/hinder subsequent destabilization through the day. Regardless, potential will exist for at least isolated severe thunderstorms Saturday afternoon, as convective initiation once again occurs across the higher terrain of NM and west TX. As thunderstorms spread eastward, occasional large hail and severe wind gusts may occur. Too much uncertainty regarding convective evolution currently exists to include greater severe hail/wind probabilities. ....Carolinas... A surface low is forecast to advance northward towards the NC/SC Coast through the period. RAP/NAM forecast soundings along the coast show generally northeasterly low-level flow for much of the day. This should tend to limit the inland advance of substantial low-level moisture, and keep appreciable severe chances offshore. ...Gleason.. 05/26/2023 $$ = = = 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) .