Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sun May 18 2025 17:34:13 ACUS02 KWNS 181734 SWODY2 SPC AC 181732 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1232 PM CDT Sun May 18 2025 Valid 191200Z - 201200Z ....THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE CENTRAL AND SOUTHERN PLAINS INTO THE OZARKS... ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM MIDDLE TENNESSEE INTO SOUTH CAROLINA... ....SUMMARY... Severe storms with all severe weather hazards are expected from the central/southern Plains into the Ozarks on Monday. ....Central/Southern Plains to the Mid-Mississippi Valley... An uncertain and potentially messy convective scenario is apparent across the region on Monday. An upper trough over the southern Rockies will become negatively tilted as it ejects across the central/southern Plains toward the Mid-MS Valley. As this occurs, a southwesterly 500 mb jet streak around 70-80 kt will overspread the region. By early evening and into the overnight hours, an 850-700 mb low-level jet will increase to around 45-55 kt. At the surface, a somewhat elongated low will extend from central NE into western KS/OK, with some forecast guidance suggesting a secondary low pressure center developing over northwest OK during late afternoon/early evening. At midday, a dryline will extend southward from central KS into western OK and central TX while a cold front develop east/southwest across NE and western KS. A warm front will extend from southeast NE into northern MO and then eastward into the Lower OH Valley. The warm front is not forecast to move much through the forecast period. Between these surface boundaries, a moisture-rich boundary layer will be in place with mid 60s to low 70s F dewpoints across a broad zone from eastern KS/OK/TX toward the Mid-South. A plume of steep midlevel lapse rates atop this moist boundary layer will result in strong destabilization by early afternoon, with MLCAPE around 2500-3500 J/kg common. Vertically veering, supercell wind profiles, becoming elongated/straight above 2-3 km will be present. Low-level hodographs initially will be somewhat small, but should become enlarged as the low-level jet increases toward evening. Capping is expected to erode by early to mid afternoon across the region. Convective evolution is uncertain. Most guidance develops quite a bit of thunderstorms rather early in the afternoon across portions of the Ozarks where 850 mb warm air advection will be maximized. While initial supercells could be possible, cell interactions and consolidation could result in some upscale development. Regardless, this initial activity will pose an all-hazards severe risk. Additional supercells are likely to develop along the surface dryline from central/eastern KS/OK where strong heating along/to the west of the boundary is expected. Convergence along the dryline is not forecast to be overly strong as low-level flow appears to remain more southerly rather than southeasterly given a lack of stronger surface cyclogenesis. This could result in a messy storm mode due to storm interactions. Nevertheless, strong instability, very steep lapse rates, and a favorably sheared environment will support significant severe storms pose an all-hazards severe risk. With time and an increasing low-level jet, one or more linear bands may develop across eastern KS/OK and move into MO/AR during the nighttime hours. A corridor of greater risk potential is possible somewhere across central/eastern OK/KS but uncertainty remains too great at this time for a categorical outlook upgrade. ....Middle TN into parts of SC... An upper ridge is forecast to be centered over the OH/TN Valley and Gulf Coast region, with modest northwesterly flow aloft spreading over the Southeast. Most guidance depicts a remnant MCV migrating through the northwest flow amid a corridor of strong instability. Deep-layer flow will be unidirectional, but speed shear will produce long/straight hodographs, with effective shear magnitudes around 25-35 kt. Modest midlevel lapse rates nearing 7 C/km, and strong surface heating leading to steep low-level lapse rates. Isolated large hail and strong/damaging gusts will be possible as convection develops southeast across the region through the afternoon. ...Leitman.. 05/18/2025 $$ = = = 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) .