Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed May 03 2023 12:45:01 ACUS01 KWNS 031244 SWODY1 SPC AC 031243 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0743 AM CDT Wed May 03 2023 Valid 031300Z - 041200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE CENTRAL AND SOUTHERN HIGH PLAINS... ....SUMMARY... Isolated severe thunderstorms are possible across portions of the central and southern High Plains this afternoon and evening. ....Synopsis... An amplified trough/ridge/trough pattern remains in place over the CONUS this morning. The eastern trough is anchored by a low currently centered over the Lower Great Lakes and western NY/PA. Expectation is for this upper low and attendant troughing to shift eastward throughout the day as a pair of shortwave troughs progress through its base across Mid-Atlantic. Western trough is anchored by an upper low currently west of San Francisco Bay. This troughing is expected to remain largely in place, while the upper low shifts gradually south-southeastward. Upper ridging will persist between these two features, extending from the southern High Plains into Alberta and Saskatchewan. Isolated thunderstorms are possible beneath this ridging from the northern Rockies into the central and southern High Plains, as increasing mid-level moisture couples with deep boundary-layer mixing to destabilize the air mass. The current surface pattern features modest ridging extending from the central Plains into the MS Valley and a low centered over northern NY. The low is forecast to follow a similar path as its parent upper low, while gradually filling. The surface ridging will shift eastward/southeastward into the mid MS Valley. Lee troughing should sharpen throughout the day, supported by persistent southwesterly flow aloft, with cyclogenesis likely over southeast CO this evening. ....Southern/Central High Plains... Gradient between the surface lee troughing and MO Valley ridge will support southerly flow across the southern Plains into the southern/central High Plains. This moisture return will help offset some of the drying related to the deep mixing anticipated. As a result, the air mass over the region is expected to be uncapped by the late afternoon. Buoyancy will be modest, but still sufficient for a few stronger storms. Large-scale ascent will be nebulous, with storms likely initiating over the higher terrain of southwestern Texas and southeastern New Mexico, and the Raton Mesa vicinity. Strong downbursts will be primary severe risk, with at least some potential for a few forward-propagating clusters this evening. ...Mosier/Wendt.. 05/03/2023 $$ = = = 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) .