Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Aug 16 2023 17:10:06 ACUS02 KWNS 161710 SWODY2 SPC AC 161708 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1208 PM CDT Wed Aug 16 2023 Valid 171200Z - 181200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS LOWER MICHIGAN...NORTHERN AND EASTERN INDIANA...WESTERN AND NORTHERN OHIO... ....SUMMARY... Isolated strong to severe thunderstorms are possible across Lower Michigan and the Ohio Valley on Thursday. ....Synopsis... A mid-level trough initially over Lake Superior and WI will move east during the period and reach the Lower Great Lakes. A belt of strong 500-mb flow (60-70 kt) moving through the base of the trough will move east across the southern Great Lakes/OH Valley overlapping a narrow warm sector during the afternoon. In the low levels, a surface low over Ontario will develop east-southeastward and weaken as a cold front pushes southeast across the Great Lakes/OH Valley. Farther west, expansive upper ridging, initially extending from the southern High Plains through the Four Corners and into the northern Intermountain West, is expected to drift eastward towards the Plains while dampening. Afternoon thunderstorms are likely beneath this ridge, predominantly over the higher terrain from northern CA across the Great Basin and into the central/southern Rockies. ....Lower MI into the OH Valley... There is high confidence and strong model agreement in a band of showers/thunderstorms extending from northern IL north-northeastward into northern Lower MI early Thursday morning. South-southwesterly low-level flow will contribute to surface dewpoints rising or being maintained in the upper 50s to low 60s deg F range prior to frontal passage. Despite some cloud cover (likely greater with north extent), some heating coupled with the marginal moisture will result in a weakly unstable airmass developing by midday. However, strong wind profiles will potentially aid in storm organization. Models indicate a second round of convection is possible a few hours after the initial band of showers/storms moves across the southern Great Lakes. Some additional heating by mid to late afternoon may yield sufficient destabilization for a greater chance for stronger storms compared to the late morning/midday activity. Relatively cool mid levels may foster an environment favorable for isolated large hail/damaging gusts before this activity weakens during the evening. ...Smith.. 08/16/2023 $$ = = = 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) .