Subj : DAY48SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Jun 25 2025 08:30:54 ACUS48 KWNS 250830 SWOD48 SPC AC 250829 Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0329 AM CDT Wed Jun 25 2025 Valid 281200Z - 031200Z ....DISCUSSION... Models are in general agreement with the upper air pattern, but increasing spread is seen from Sunday/D5 and beyond. On Saturday/D4, a low amplitude wave will lift out of the ND/northern MN vicinity and move into Ontario. This will result in temporary height rises during the day before gradual falls occur overnight and into as a secondary wave moves from MT into the Dakotas overnight. Early day storms may exist over parts of northern MN in association with the low-level jet, and this activity could weaken during the day. Then, strong instability is forecast for several models, perhaps MUCAPE to around 5000 J/kg, over eastern SD and NE and into IA and MN. Heating within the surface trough may spur afternoon development from SD into NE, with some potential for activity to spread east/northeast. However, shear will likely be weak, with 500 mb winds averaging around 15 kt. Despite very strong instability, the weak-forcing situation in the wake of the exiting wave suggests low-predictability at this time. Around Sunday/D5, the secondary wave is forecast to amplify across the upper MS Valley and upper Great Lakes, with a cold front pushing south and extending roughly from WI to NE. Strong instability will likely exist ahead of such a boundary, though shear will again be weak. Still, storms will likely develop across the region, with areas of damaging gusts potential. From Monday/D6 through Wednesday/D8, the aforementioned trough will spread across the Great Lakes and Northeast, with what appears to be an end to the extreme instability levels. Scattered storms will likely persist over much of the Southeast and Mid Atlantic, with sporadic strong gusts daily. ...Jewell.. 06/25/2025 = = = 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) .