Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Feb 21 2023 12:02:10 ACUS01 KWNS 211202 SWODY1 SPC AC 211200 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0600 AM CST Tue Feb 21 2023 Valid 211300Z - 221200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS PARTS OF THE MID-ATLANTIC AND WESTERN NORTH TX TO CENTRAL OK... ....SUMMARY... Isolated thunderstorms capable of damaging winds will be possible across parts of the Mid-Atlantic from about Noon to 4 PM EST. Isolated severe wind and hail will be possible after 2 AM CST across a portion of western north Texas into central Oklahoma. ....Mid-Atlantic... In the wake of an initial frontal wave migrating offshore, boundary-layer warming east of the Allegheny Mountains, coupled with modest residual low-level moisture characterized by low 40s surface dew points, should contribute to weak destabilization by early afternoon. Ascent tied to an approaching shortwave impulse from the Great Lakes and OH Valley will aid in scattered low-topped convection towards midday across central PA into the eastern WV Panhandle. As this activity spreads into the meagerly buoyant but steep lower-level lapse rate environment, small hail and strong gusty winds are anticipated. With stronger 700-mb westerlies progged across far southern portions of PA/NJ into VA, have expanded the cat 1-MRGL risk southward. ....Southern Great Plains... A narrow corridor of meager boundary-layer destabilization with MLCAPE of 250-500 J/kg is anticipated in the early morning Wednesday ahead of a sharpening cold front ejecting east from the High Plains. Strengthening forcing for ascent downstream of an elongated shortwave trough over the southern High Plains will support increasing convective development, especially in the 09-12Z time frame. Current CAM guidance suggests that convection will begin to organize into a QLCS along the front around to just after 12Z, amid indications of P-shaped hodographs within the residual elevated mixed-layer (near 850-700 mb). The strongest thunderstorms through 12Z may pose a threat for isolated severe wind and hail. ....East-central IL to southwest OH... A swath of elevated convection should develop early Wednesday morning amid strengthening lower-level warm theta-e advection. Most of this activity should occur within scant elevated buoyancy, but strong speed shear through the cloud-bearing layer may support small hail in the more robust updrafts. ...Grams/Gleason.. 02/21/2023 $$ = = = 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) .