Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue May 02 2023 16:55:54 ACUS02 KWNS 021655 SWODY2 SPC AC 021654 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1154 AM CDT Tue May 02 2023 Valid 031200Z - 041200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM SOUTHWEST TEXAS TO FAR EASTERN COLORADO AND WESTERN KANSAS... ....SUMMARY... Isolated to widely scattered strong to severe thunderstorms capable of strong gusts and large hail are possible Wednesday afternoon and evening across the central and southern High Plains. ....Southern/Central High Plains... An upper ridge will be centered over the Rockies and adjacent High Plains on Wednesday. Various weak impulses related to remnants of Day 1/Tuesday convection will be shifting east across KS/OK early in the period. Thereafter, forcing for ascent will remain nebulous until late in the period when a shortwave impulse is forecast to eject into the southern Rockies/High Plains vicinity after 03z. This later impulse will be ill-timed for diurnal convection. Modest boundary-layer moisture (surface dewpoints from the mid 50s to low 60s F) is forecast from southwest TX northward through the OK/TX Panhandles and into far eastern CO/western KS. Steep midlevel lapse rates will contribute to MLCAPE values around 1500-2000 J/kg, with much of the instability focused above 700 mb atop a weak EML. Deep-layer flow also will remain fairly weak beneath the upper ridge, though favorable veering with height will be sufficient for effective shear values near 30 kt. Strong heating and low-level convergence should be sufficient to support isolated thunderstorm development by afternoon. Shear will be marginally favorable for transient supercells and clusters. Elongated hodographs above 2-3 km coupled with favorable thermodynamic profiles suggest large hail will be possible with any sustained semi-discrete convection. Steep low-level lapse rates also may support isolated strong downburst winds. Modestly enlarged low-level hodographs and around 100 J/kg 0-3km MLCAPE typically would indicate some potential for a tornado. However, given modest boundary-layer moisture and weak 0-1 km shear, the tornado threat is expected to remain minimal. ....Oregon/Washington... Modest heating/destabilization will again support thunderstorm development across parts of the interior Northwest on Wednesday. Guidance still suggests that a midlevel shortwave trough embedded within the broader cyclonic flow may be favorably timed for storm development during the late afternoon/evening across western/northern OR into southern WA. Some uncertainty regarding low-level moisture, and hence degree of destabilization, is evident in forecast surface dewpoints. The operational NAM remains more aggressive with boundary-layer dewpoints compared to most other guidance. While some low severe potential may develop (mainly for hail), current expectation is for a few strong storms capable of mainly small, sub-severe hail. ...Leitman.. 05/02/2023 $$ = = = 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) .