Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Mon Jul 03 2023 17:32:17 ACUS02 KWNS 031732 SWODY2 SPC AC 031730 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Mon Jul 03 2023 Valid 041200Z - 051200Z ....THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS NORTHERN KANSAS AND SOUTHERN NEBRASKA... ....SUMMARY... Scattered severe thunderstorms are forecast over central Great Plains beginning late afternoon Tuesday into Tuesday night. Severe thunderstorm gusts will be the primary hazard. ....Synopsis... A weak upper trough is forecast to shift slowly eastward across New England Tuesday, while farther west, a more pronounced area of cyclonic flow will continue to expand across portions of the Intermountain West and northern/central Plains area. At the surface, a weak front will linger across the East Coast and Gulf Coast states, while a stronger cold front will move east across the Upper Midwest southwestward through portions of the central High Plains. ....Upper MS Valley southwestward to the central High Plains... Isolated to scattered showers/thunderstorms will probably be ongoing across the Upper Midwest near/behind the front during the morning. This early day activity will likely weaken with moderate destabilization forecast on the periphery of any morning convective outflow ahead of the front. A slowly advancing, northeast-to-southwest cold front will be the focus for renewed thunderstorm activity during the afternoon. While stronger flow aloft will remain to the west of the Upper Mississippi to Mid-Missouri Valley portion of the front, multicell storm clusters evolving with time will pose risk for locally damaging winds and hail. Farther to the southwest, into the central High Plains, easterly upslope flow just to the cool side of the front beneath 20 to 35 kt 500-mb westerlies will yield shear supporting a mix of supercells and multicells. Thunderstorms will likely develop near the higher terrain of the Colorado Front Range/higher terrain of southeast Wyoming by early afternoon. This convection will gradually push east into the adjacent High Plains by mid-late afternoon with a corresponding increase in storm coverage. Concurrently, weakening convective inhibition due to strong heating near the front over NE will lead to scattered thunderstorms developing by late afternoon over the Nebraska Sandhills. Forecast soundings show very steep surface-400 mb lapse rates (8+ deg C/km) ahead of the front. The latest model guidance suggests increasing storm coverage by early evening with several clusters evolving from northeast Colorado into northwest Kansas and a separate adjacent area over southwest into central Nebraska. Both regimes may merge during the evening with severe gusts being the primary hazard, including the possibility of peak gusts 70-85 mph. This notion of significant severe gusts seems supported by some of the latest CAM guidance. This severe cluster/MCS will push east near the Kansas/Nebraska border during the overnight with a gradual weakening trend expected. ....Portions of the East Coast Region and Southeast into north TX... Diurnal heating/destabilization near and ahead of the weak/slow-moving front extending southwestward across the Eastern Seaboard, and westward across the southeast will result in scattered thunderstorm development. While modest deep-layer shear suggests generally disorganized convection, moderate west-southwesterlies through the lower and middle troposphere may promote a few eastward-propagating clusters of storms, where potential for strong/gusty outflow winds may be relatively maximized. Overall however, hail/wind potential should remain isolated, confined to generally disorganized storms into the evening hours. Have added low-severe probabilities westward into the southern Great Plains to account for at least isolated thunderstorms developing during the late afternoon/early evening. A more deeply mixed profile compared to farther east (Mississippi/Alabama) may foster isolated severe gusts and perhaps marginally severe hail with the more intense storms. ...Smith.. 07/03/2023 $$ = = = 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) .