Subj : DAY48SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Thu Mar 20 2025 09:00:25 ACUS48 KWNS 200900 SWOD48 SPC AC 200858 Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0358 AM CDT Thu Mar 20 2025 Valid 231200Z - 281200Z ....DISCUSSION... ....Sunday/Day 4 and Monday/Day 5... A large-scale cyclonic flow pattern will be in place across much of the continental U.S. on Sunday. An upper-level low will develop over the Great Lakes, as an associated trough moves southeastward from the Great Plains to the Mississippi Valley. A cold front is forecast to move southeastward into the Ozarks. Ahead of the front, moisture advection is forecast to occur over the Sabine and lower Mississippi Valleys, where surface dewpoints will likely be in the 60s F and moderate instability is expected to develop. Scattered thunderstorms appear likely to initiate ahead of the front Sunday evening from the Sabine River Valley northeastward into the Tennessee Valley, with an MCS developing Sunday evening. Moderate deep-layer shear will likely support severe thunderstorm development, with a potential for severe wind gusts, isolated large hail. A tornado threat may also develop. A cold front is forecast to move through the Gulf Coast region Sunday morning. Isolated severe storms could develop ahead of the front early in the day from the Texas Coast eastward to the central Gulf Coast and Florida Panhandle. Predictability remains low concerning where the greatest severe threat will be along this corridor. The severe threat should end during the day as the front moves southward into the Gulf. ....Tuesday/Day 6 to Thursday/Day 8... On Tuesday, a mid-level trough is forecast to dig southeastward into the Mississippi Valley. At the surface, a moist airmass will remain over the Gulf Coast region. Isolated strong to severe storms could occur along the northern edge of this moist airmass. The greatest potential for severe could be across the Sabine River Valley, where some solutions have moderate instability Tuesday afternoon. This appears to be a conditional severe threat, and predictability is low. From Wednesday into Thursday, a relatively dry airmass is forecast over much of the nation. The exception could be across south Texas, where thunderstorm development will be possible. Although an isolated severe threat would be possible there, predictability at this extended range in the forecast cycle is low. ...Broyles.. 03/20/2025 = = = 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) .