Subj : DAY3SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sun Apr 20 2025 19:28:04 ACUS03 KWNS 201927 SWODY3 SPC AC 201926 Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0226 PM CDT Sun Apr 20 2025 Valid 221200Z - 231200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE SOUTHERN HIGH PLAINS... ....SUMMARY... Isolated severe thunderstorms are possible on Tuesday across portions of the southern Plains. ....Synopsis... Modest west-southwesterly flow is forecast from the Southwest to the southern Plains on Tuesday with a stronger mid-level jet across the northern Plains and a sharpening trough in the Pacific Northwest. A weak mid-level shortwave trough (indicated by most guidance) is forecast to cross New Mexico during the afternoon which would result in a sharpening dryline and perhaps some lee cyclogenesis. ....Southern High Plains into southern Kansas... Low-level moisture advection and strong heating across the southern High Plains will lead to moderate to strong destabilization ahead of the dryline. As this airmass becomes uncapped by early to mid-afternoon and ascent increases ahead of the approaching mid-level shortwave trough, expect scattered thunderstorm development. A deeply mixed boundary layer and 25 to 35 knots of shear will support supercells capable of large hail and severe wind gusts. Storms will likely congeal into an MCS by later in the evening as the low-level jet strengthens with some severe wind threat which could continue into the overnight hours. A remnant frontal boundary will likely be in place across southern Kansas Tuesday afternoon which will likely be an additional focus for potential severe storms Tuesday afternoon. Moisture/instability remains more questionable across southern Kansas, and shear is not forecast to be quite as strong amid somewhat veered low-level flow ahead of the front. Therefore, a marginal risk (level 1 of 5) has been maintained at this time. ....Central Iowa to southern Wisconsin and Northern Illinois... Moisture recovery along a warm frontal zone may lead to some weak instability from eastern Iowa into southern Wisconsin and northern Illinois. Sustained isentropic ascent may provide sufficient forcing for isolated to scattered thunderstorm development through the day. Despite the lack of moisture, cool temperatures aloft and steep lapse rates may support the potential for isolated large hail and damaging wind gusts. ...Bentley.. 04/20/2025 $$ = = = 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) .