Subj : DAY48SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sun Jun 25 2023 08:56:44 ACUS48 KWNS 250856 SWOD48 SPC AC 250855 Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0355 AM CDT Sun Jun 25 2023 Valid 281200Z - 031200Z ....DISCUSSION... ....Wednesday/Day 4 and Thursday/Day 5... An upper-level trough is forecast to move eastward from the northern Plains into the upper Mississippi Valley on Wednesday, reaching the Great Lakes on Thursday. Ahead of the system, a moist airmass is forecast from the northern Plains into the mid to upper Mississippi Valley. On Wednesday, the models suggest that a severe threat will be possible ahead of the upper-level trough in the upper Mississippi Valley. Model consensus places the greatest convective coverage in Minnesota, near the northern edge of the stronger instability. Isolated severe storms would also be possible further south into parts of the mid Missouri Valley. However, the short-wave trough is forecast to be subtle, and at the northern edge of an anticyclone. This introduces considerable uncertainty. The potential for severe is forecast to shift eastward on Thursday, but could be more isolated as the shortwave trough outruns the instability axis. If another shortwave trough can develop and move into the northern Plains, an additional severe threat area would be possible. However, predictability is too low to add a threat area on either Wednesday or Thursday. ....Friday/Day 6 to Sunday/Day 8... An anticyclone in the central U.S. is forecast to gradually breakdown over the weekend, as an upper-level trough develops in the north-central U.S. A moist airmass should remain over the Ohio and Tennessee Valleys, where scattered thunderstorms are expected Friday afternoon and evening. A severe threat will be possible at the northern edge of the moist airmass in parts of the Ohio Valley in the afternoon. The potential for severe storms could continue across the same general area on Saturday, as a shortwave trough moves across the region. On Sunday, scattered thunderstorms will again be possible in many areas from the Mississippi Valley eastward across the Ohio and Tennessee Valleys. At this point, confidence is low regarding any potential scenarios over the weekend. ...Broyles.. 06/25/2023 = = = 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) .