Subj : DAY48SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue May 27 2025 08:59:59 ACUS48 KWNS 270859 SWOD48 SPC AC 270858 Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0358 AM CDT Tue May 27 2025 Valid 301200Z - 041200Z ....DISCUSSION... ....Friday/Day 4 to Sunday/Day 6... On Friday, a mid-level trough is forecast to move eastward from the mid Mississippi Valley into the eastern U.S. At the surface, a moist airmass is forecast to be located from the Gulf Coast states northeastward into the Carolinas, where moderate instability should be in place by afternoon. Ahead of the trough, large-scale ascent should support scattered thunderstorm development, with the greatest convective coverage expected from Georgia northeastward into the Carolinas. Model forecasts suggest that moderate deep-layer shear will exist ahead of the trough, which will contribute to a possibility for severe storms from mid afternoon into the early evening. Large hail and wind damage would be the primary threats. On Saturday and Sunday, a cold front is forecast to move southward across the Gulf of America, as northwesterly mid-level flow develops over the central U.S. A shortwave trough is forecast to move southeastward from the central Plains on Saturday into the lower Mississippi Valley on Sunday. Scattered thunderstorms should develop ahead of a shortwave trough each afternoon and evening. An isolated severe threat will be possible. However, the combination of instability and deep-layer shear is not expected to be sufficient for a greater severe threat. ....Monday/Day 7 and Tuesday/ Day 8... A pronounced mid-level ridge is forecast to develop on Monday across the central U.S., with the ridge moving eastward into the Great Lakes on Tuesday. In the wake of the ridge, strong to severe thunderstorm development will be possible over parts of the northern Plains Monday afternoon and evening. On Tuesday, model forecasts suggest that scattered thunderstorm development could take place ahead of the trough in the upper Mississippi Valley, with additional storm development over the lower to mid Missouri Valley. Although a severe threat may develop, predictability for early next week is low at this time. ...Broyles.. 05/27/2025 = = = 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) .