Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Mon Oct 28 2024 20:28:04 ACUS02 KWNS 282027 SWODY2 SPC AC 282026 Day 2 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 0326 PM CDT Mon Oct 28 2024 Valid 291200Z - 301200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE UPPER MISSISSIPPI AND MIDDLE MISSOURI VALLEYS TO KANSAS/NORTHWESTERN OKLAHOMA... CORRECTED FOR THUNDER AREA REMOVAL IN THE NORTHEAST ....SUMMARY... Thunderstorm development may begin late in the period from the Upper Mississippi Valley area south-southwestward across the Plains. Local/limited risk for hail/wind warrants continuation of Level 1/MRGL risk for Tuesday night. ....Synopsis... A highly amplified flow field aloft will reside across the U.S. Tuesday, as a deep trough slowly crosses the Intermountain West through the period. By Wednesday morning, the trough should extend from the northern High Plains to the Four Corners area. Meanwhile, ridging will amplify in the eastern U.S., in response to the advance of the western trough. At the surface, a cold front will sweep across the Four Corners states through the first half of the period, ahead of the progressing upper system. A frontal wave should evolve over the central High Plains, and is expected to then shift north-northeastward across Nebraska, reaching the southern Minnesota vicinity by 12Z Tuesday morning. This will allow continued eastward advance of the trailing front, which should extend from the Mid Missouri Valley (western Iowa) vicinity south-southwestward to southern New Mexico/far West Texas by the end of the period. ....Upper Mississippi Valley south-southwestward to the northwestern Oklahoma vicinity... Ahead of the sharpening cold front becoming established across the Plains Tuesday/Tuesday night, a warm/modestly moist pre-frontal boundary layer is expected to evolve, beneath a fairly pronounced warm/capping layer aloft. Much of the large-scale ascent associated with the advancing upper system should remain to the cool side of the front, and thus expect the capping layer to be very slow to weaken/erode. Low-level warm advection ahead of the track of the surface low may support some primarily elevated convective development overnight, where modest elevated CAPE may be sufficient to permit a few stronger updrafts. Limited potential for hail nearing severe levels could accompany one or two of the strongest storms. A strong gust cannot be ruled out, should a less-elevated storm nearer the surface boundary evolve. Farther southwestward into the Plains, any potential storm development should be limited to the last 3 or 4 hours of the period, at the earliest -- due to the persistent capping. With that said, given gradually steepening lapse rates/increasing CAPE, and the presence of strong southwesterly flow aloft atop the frontal zone, low/conditional risk for a couple of storms capable of producing marginal hail/wind cannot be ruled out. A such, will retain an elongated Level 1/MRGL risk area across central portions of the country to reflect these potential convective scenarios that may evolve prior to the end of the period. ...Goss.. 10/28/2024 $$ = = = 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) .