Subj : DAY3SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Fri May 05 2023 07:27:16 ACUS03 KWNS 050727 SWODY3 SPC AC 050726 Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0226 AM CDT Fri May 05 2023 Valid 071200Z - 081200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF NORTHERN MISSOURI AND IOWA... ....SUMMARY... Severe storms with large hail and wind damage will be possible across parts of the Upper Midwest on Sunday. Marginally severe storms will also be possible in parts of the southern and central Plains, and across parts of the southern Great Lakes and upper Ohio Valley. ....Upper Midwest... An upper-level ridge is forecast across the western Great Lakes on Sunday, as southwest flow remains in the mid-levels across much of the Great Plains and Mississippi Valley. A moist airmass will likely be located from eastern parts of the central Plains northeastward into the mid to upper Mississippi Valley, where it appears that moderate instability will develop by afternoon. Scattered thunderstorms may form during the mid to late afternoon in areas that heat up the most and along pre-existing boundaries. Forecast soundings for late Sunday afternoon along the northern edge of the moist sector, from Iowa into far northern Missouri, have 0-6 km shear from 40 to 45 knots, with gradually veering winds with height. Also, mid-level lapse rates are forecast to be in the 7.5 to 8.5 C/km range. This environment would easily support severe storms, with supercell and short bowing line segments possible. Large hail and wind damage would be the primary threats. ....Southern and Central Plains... Southwesterly flow in the mid-levels is forecast to continue across much of the central U.S. on Sunday. At the surface, a moist airmass will be located across much of Texas, Oklahoma and eastern Kansas. Moderate to strong instability will likely develop across parts of this moist airmass by afternoon. Thunderstorms may form during the afternoon in areas where low-level convergence becomes maximized. Although large-scale ascent and deep-layer shear will remain relatively weak, an isolated severe threat will still be possible, especially near pockets of strong instability. Marginally severe winds and hail will be the primary threats. ....Southern Great Lakes/Upper Ohio Valley... An upper-level ridge is forecast to remain over the western Great Lakes on Sunday. Flow at mid-levels should be northwesterly across the eastern Great Lakes and upper Ohio Valley. Model forecasts suggest that a gradient of instability will develop behind a warm front during the day from southern Michigan southeastward across Ohio. Convection that can initiate along this gradient of instability during the afternoon, may have a chance to become marginally severe. Strong wind gusts and hail would be the primary threats. ...Broyles.. 05/05/2023 $$ = = = 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) .