Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Apr 17 2024 05:58:05 ACUS01 KWNS 170557 SWODY1 SPC AC 170556 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1256 AM CDT Wed Apr 17 2024 Valid 171200Z - 181200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE OHIO VALLEY AND LOWER GREAT LAKES...AND IN PARTS OF NORTHEAST KANSAS AND WESTERN MISSOURI... ....SUMMARY... Scattered thunderstorms, capable of wind damage, isolated large hail and a tornado threat, are expected to develop across parts of the Ohio Valley and Lower Great Lakes this afternoon. Storms with large hail are expected tonight in parts of the central Plains and Ozarks. ....Ohio and Tennessee Valleys/Central Gulf Coast States... A negatively tilted upper-level trough, and an associated surface low, will move into the Great Lakes today. A corridor of maximized surface dewpoints will move eastward across the Ohio Valley today, as a cold front approaches from the west. Scattered thunderstorms will likely develop during the late morning, as low-level convergence and instability increases. These storms, in the form of clusters or short line segments, will move eastward across the Ohio Valley and Lower Great Lakes region during the afternoon. RAP forecast soundings across far eastern Indiana and western Ohio during the early afternoon show a favorable environment for severe storms, with MLCAPE near 1500 J/kg and 0-6 km shear around 50 knots. This should support an isolated large hail threat with the more discrete rotating storms. A wind-damage threat will also be possible, especially with the more organized line segments. Forecast soundings suggest that low-level shear will become more favorable in the late afternoon, with 0-3 km storm-relative helicity increasing into the 225 to 250 m2/s2 range. For this reason, the tornado threat is expected to be greater a bit further east from central and eastern Ohio into far western Pennsylvania. Further south into the Tennessee Valley and central Gulf Coast states, isolated thunderstorms are expected to develop ahead of a cold front, and near a moist axis with surface dewpoints in the 60s F. MLCAPE in the 750 to 1000 J/kg range, along with 0-6 km shear from 40 to 50 knots will be sufficient for an isolated severe threat. Marginally severe wind gusts and hail will be the primary threats. ....Central Plains/Ozarks... An upper-level trough will move through the north-central U.S. tonight, as a 70 to 80 knot mid-level jet passes through the trough. In response, a 40 to 50 knot low-level jet will develop further south across the central Plains. Thunderstorms are expected to initiate near the northern edge of the low-level jet late this evening from central Kansas into far southeast Nebraska. These storms are expected to move eastward across northeast Kansas and into western Missouri. Forecast soundings in northeast Kansas around 06Z have MUCAPE near 2500 J/kg, with effective shear around 45 knots. This, combined with 700-500 mb lapse rates around 7.5 C/km, should be favorable for elevated rotating storms with potential for very large hail. The large hail threat is expected to be greatest in the 04Z to 07Z time window, but may persist through late in the period. ...Broyles/Lyons.. 04/17/2024 $$ = = = 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 3.20-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .