Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sat Jun 24 2023 06:02:03 ACUS02 KWNS 240601 SWODY2 SPC AC 240600 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Sat Jun 24 2023 Valid 251200Z - 261200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE MID MISSISSIPPI...OHIO AND TENNESSEE VALLEYS... ....SUMMARY... A severe threat will be likely across parts of the mid Mississippi, Ohio and Tennessee Valleys on Sunday. Large hail, wind damage and perhaps a couple tornadoes will be possible. ....Mid Mississippi Valley/Ohio and Tennessee Valleys... An upper-level trough will move eastward into the western Great Lakes region on Sunday, as a 50 to 60 knot mid-level jet noses into the Ohio Valley. At the surface, a cold front will advance southeastward into the mid Mississippi Valley. Ahead of the front, surface dewpoints in the upper 60s and lower 70s F will contribute to corridor of strong instability by afternoon. In the early afternoon, convection is forecast to first initiate across eastern Illinois, far western Indiana and lower Michigan. From this convection, thunderstorms are expected to form and move east-southeastward across the Ohio Valley. MCS development will be possible, with a large convective cluster or line of storms affecting much of Kentucky, Tennessee and northeastern Arkansas. The exit region of the mid-level jet will overspread the Ohio Valley during the late afternoon, enhancing lift and contributing to strong deep-layer shear. NAM forecast soundings in the vicinity of Louisville, Kentucky in the late afternoon, beneath the nose of the mid-level jet, have MLCAPE peaking near 4000 J/kg. 0-6 km shear is forecast to be near 50 knots, with 0-3 km storm relative helicity generally near or above 300 m2/s2. This should support supercells capable of producing large hail, wind damage and a tornado threat. It appears that supercells with large hail will be most likely early in the event, but that the potential for severe multicell line segments with damaging wind gusts may increase later in the event. A lot will depend upon whether a linear MCS can become organized, and how quickly a cold pool can develop. There is also uncertainty concerning the exact track of a potential MCS, the timing of the upper-trough and distribution of instability. An area of higher wind-damage threat could be later added once these factors become more clear. Further west into northern Arkansas, isolated thunderstorms are expected to develop during the late afternoon. Although instability and deep-layer shear are forecast to be adequate for severe storms, warm temperatures aloft and more limited large-scale ascent may keep any severe threat marginal. ...Broyles.. 06/24/2023 $$ = = = 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) .