Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Thu Jun 01 2023 05:32:08 ACUS02 KWNS 010531 SWODY2 SPC AC 010530 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 AM CDT Thu Jun 01 2023 Valid 021200Z - 031200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF WESTERN TEXAS... ....SUMMARY... Strong to severe thunderstorms capable of producing large hail, strong gusts and a couple of tornadoes are possible Friday afternoon and evening across parts of the southern High Plains. ....Southern Plains vicinity... A midlevel shortwave trough will shift east across the southern Plains on Friday. As this occurs, 500 mb temperatures cooling to around -10 to -12 C, resulting in steepening midlevel lapse rates, will overspread western portions of Texas into western OK. A belt of enhanced west/southwesterly midlevel flow associated with this feature, atop southeasterly low-level flow, will create favorable vertically veering wind profiles, with 40+ kt effective-shear magnitudes supporting supercell structures. Southeasterly low-level flow will allow for low/mid 60s F dewpoints as far west as the TX/NM border along a surface trough. Strong heating, especially from the Big Bend toward the South Plains vicinity, will support a corridor of strong destabilization by afternoon (2000-3000 J/kg MLCAPE). A mix of discrete supercells and organized clusters is expected by late afternoon and continuing into the evening. Elongated hodographs, in the presence of steep midlevel lapse rates/large CAPE, and favorable midlevel shear suggest large to very large hail will be possible, especially with more discrete convection. Steep low-level lapse rates and modest low-level shear also will support strong downburst winds. Damaging-wind potential may increase toward evening as some guidance suggests a bowing MCS could develop eastward across the Slight risk (level 2 of 5) area. This evolution is a bit uncertain, given a lack of a strong low-level jet response in most forecast guidance. However, if a strong-enough cold pool in generated, some upscale development seems plausible during the evening. While low-level shear will generally be modest, some augmentation to strength of low-level shear is possible near a surface low developing near the NM/TX border. Increased 0-3 km SRH along this corridor will support a relative max in tornado potential. Vertical shear will weaken with northward extent into OK and KS, and strong large-scale ascent will remain focused over west TX. This may limit longevity of more intense/organized cells developing during the late afternoon with northward extent. Nevertheless, moderate instability/shear will still support isolated strong/severe storms from western OK into southern KS. ....Northeast... Generally weak deep-layer northerly flow will persist across the region on the eastern periphery of a Great Lakes upper anticyclone. Some modest midlevel cooling and weak ascent associated with an approaching shortwave trough from Quebec, in combination with seasonal moisture/instability will support isolated thunderstorms during the afternoon. Vertical shear will remain very weak, limiting longevity and organization of strong updrafts. Nevertheless, steep midlevel lapse rates and well mixed boundary-layer could foster a few strong gusts and small hail in stronger cells. ...Leitman.. 06/01/2023 $$ = = = 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) .