Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Aug 14 2024 17:29:15 ACUS02 KWNS 141729 SWODY2 SPC AC 141727 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1227 PM CDT Wed Aug 14 2024 Valid 151200Z - 161200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN KS INTO PARTS OF THE MID MS VALLEY AND MIDWEST... ....SUMMARY... Scattered severe thunderstorms appear possible across parts of the Midwest, mid Mississippi Valley, and central Plains on Thursday. Damaging winds and large hail should be the main threats, but a couple tornadoes may also occur. ....Synopsis... A mid/upper-level trough is forecast to evolve into a closed low on Thursday over parts of central/northern MN. As this occurs, a surface low will move from parts of MN/IA toward the upper Great Lakes, as a trailing cold front moves through parts of the upper Midwest into the central/southern Great Plains. ....Midwest into the mid MS Valley vicinity... In the wake of morning convection, moist low-level southwesterly flow will support airmass recovery and robust destabilization by afternoon from parts of the east-central Plains into the mid MS Valley and Midwest. MLCAPE may increase into the 2500-4000 J/kg range, while some increase in midlevel flow across the warm sector will support effective shear of 30-45 kt, resulting in a conditionally favorable severe-thunderstorm environment across a relatively broad region. The details of convective development and evolution continue to be uncertain, with generally weak convergence expected along the primary front, and with the location of any outflow boundaries yet to be determined. However, isolated to widely scattered storm development will be possible during the afternoon and early evening, both near the front and any other remnant boundaries. A somewhat greater coverage of storms will be possible later Thursday evening from southern WI into parts of IL/MO, in response to a midlevel jet maximum moving through the base of the trough. Supercells with a threat of large hail, damaging wind, and a couple tornadoes will be possible with initial development during the afternoon and early evening, with some upscale growth and an increase in damaging-wind potential possible later in the convective evolution. Some threat for at least isolated damaging wind could persist into Thursday night, though the southern/eastern extent of any organized severe potential remains uncertain. ....Eastern NE into western/central IA... There is some signal for at least isolated storm development within a post-frontal regime across parts of NE/IA and vicinity, which would potentially be aided by a low-amplitude shortwave moving through the base of the larger-scale trough. The post-frontal environment will remain favorable for organized convection, with moderate to locally strong buoyancy and favorable midlevel lapse rates and deep-layer shear. Some threat for large hail and localized damaging wind could accompany any robust storms within this regime during the afternoon and evening. Greater severe probabilities may be needed for parts of this region if confidence in this scenario increases. ....Southern KS into OK... With robust daytime heating, a deeply mixed boundary layer is expected to develop along/south of the front across parts of southern KS into OK. While deep-layer shear should remain weak across most of this region, moderate to strong instability and steepened low to mid-level lapse rates should support mainly an isolated severe wind threat with high-based thunderstorms that can develop. Occasional hail may also occur with the strongest cores. ...Dean.. 08/14/2024 $$ = = = 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) .