Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Mar 29 2023 17:30:15 ACUS02 KWNS 291730 SWODY2 SPC AC 291728 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1228 PM CDT Wed Mar 29 2023 Valid 301200Z - 311200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF THE SOUTHERN/CENTRAL PLAINS AND THE UPPER MIDWEST... ....SUMMARY... Isolated strong to severe storms are possible over parts of the southern and central Plains Thursday evening and overnight. ....Synopsis... Amplified mid-level flow is expected across much of the CONUS as an active flow regime continues. An anomalously deep upper-level cyclone over the West Coast is forecast to shift eastward across the Southwest as it transitions toward an open wave through Thursday. A lee cyclone over eastern CO should deepen as lift from the trough and an 80-90 kt jet streak overspreads the southern/central Rockies and High Plains. To the east, shortwave ridging over the Southeast will support broad southerly return flow across the center of the country. A warm front will rapidly lift poleward extending into KS/NE by the end of the period. Weak destabilization and strong shear near and south of the front may support isolated severe thunderstorms ahead of the deepening surface cyclone across the central and southern Great Plains Thursday evening into the overnight hours. ....Southern Plains... As the upper trough begins to eject eastward out of the Southwest over the Rockies and High Plains, large-scale ascent from the advancing polar jet streak/trough is forecast to generally lag behind the returning warm sector farther east. Despite rapid northward advection of upper 50s to low 60s F surface dewpoints, perhaps as far north as KS/OK by 00z, considerable inhibition is expected during the daylight hours across much of the southern Plains. This should generally suppress surface based thunderstorms until after sunset, though a conditional risk for a supercell will remain possible primarily across southwestern OK. A few elevated cells may develop with a small southern stream perturbation passing over portions of eastern OK with a risk for hail and or wind. Gradually increasing forcing for ascent ahead of the advancing Pacific front/dryline may allow for isolated thunderstorms to develop near the Red River in south-central/southeastern OK and track east northeastward overnight. While likely somewhat stable in the low levels, increasing vertical shear supportive of organized storms, including supercells, may promote a risk for isolated hail and damaging gusts. ....Central Plains and Midwest... Farther north, large-scale forcing will arrive earlier in the diurnal cycle across portions of eastern NE/SD into the upper Midwest, but the low-levels will remain mostly stable at the tip of the moist plume rapidly advecting north. As a result, limited buoyancy (generally less than 500 J/kg of MUCAPE) is expected despite steeper mid-level lapse rates beneath the cold core of the trough. Isolated elevated thunderstorms may develop late in the afternoon from eastern NE into southern SD capable of some severe hail given favorable shear profiles for supercells. As the main trough continues eastward, low-level mass response from the deepening surface low should allow for more widespread thunderstorms to develop after dark. Elevated thunderstorms should develop in an arc near the core of the low-level jet from western IA, toward southwestern MN. Severe hail may develop north of the warm front through the overnight and into early Friday Morning. Additional elevated thunderstorms are possible farther east over portions of northern and central IL, but confidence in severe potential here is lower owing to weaker forcing and more limited lapse rates aloft. ...Lyons/Jewell.. 03/29/2023 $$ = = = 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) .