Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Aug 23 2023 17:32:20 ACUS02 KWNS 231732 SWODY2 SPC AC 231730 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Wed Aug 23 2023 Valid 241200Z - 251200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR THE SOUTHERN GREAT LAKES...CENTRAL APPALACHIANS...AND NORTH DAKOTA... ....SUMMARY... Isolated severe thunderstorms are possible across the southern Great Lakes and central Appalachians, and North Dakota late Thursday afternoon into Thursday night. ....Southern Great Lakes into the central Appalachians... A mid-level high over southern OK will maintain a suppressive influence on deep convective development across much of the central U.S. eastward towards the TN Valley. A belt of moderate west-northwesterly mid-level flow will extend from the Upper Great Lakes east-southeastward to the northern portion of the Mid-Atlantic region. In the low levels, a cold front will push southeast across the central Great Lakes into the Lower Great Lakes and provide a focus for thunderstorm development. Very warm mid-level temperatures on the northeast periphery of the mid-level anticyclone will likely inhibit convective development for much of the day. However, associated with the elevated mixed layer over the southern Great Lakes, steep 700-500 mb lapse rates and a very moisture-rich airmass will contribute to moderate to extreme instability developing by mid afternoon. Model guidance indicates at least isolated to scattered storms will develop near the Lake Erie vicinity on the northeast periphery of stronger capping. It remains unclear on the overall coverage/placement and subsequent evolution of storms in the Lower Great Lakes/upper OH Valley. If a cluster can develop and become surface-based, a potentially greater risk for severe may occur (i.e., upper OH Valley/Lake Erie vicinity). This activity will probably grow upscale into the central Appalachians during the evening into the overnight and perhaps maintain a risk for damaging gusts/large hail. Farther west across the southern Great Lakes, the surface boundary will become more diffuse with west extent near the MS River. Very hot conditions may overcome the weakly forced setup and result in a few storms from Michiana westward into far eastern IA. Severe gusts and perhaps large hail will be the primary threats with these potential storms. ....ND... A mid-level shortwave trough over Alberta/Saskatchewan will pivot southeast towards the Canadian/ND border by early evening and into northern MN by daybreak Friday. A weak front will push southeast into ND by mid afternoon. Steep low- to mid-level lapse rates and dewpoints ranging from the 50s west to low-mid 60s over eastern ND, will result in weak to moderate buoyancy. The latest model guidance indicates isolated to scattered storms developing near the boundary by early evening. Elongated hodographs will aid in storm organization (i.e., organized multicells and a few supercells). Isolated large hail and severe gusts are the primary risks with the stronger storms. Some of this activity may linger into the overnight as it moves east across ND late. ...Smith.. 08/23/2023 $$ = = = 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) .