Subj : DAY48SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Apr 11 2023 09:01:30 ACUS48 KWNS 110901 SWOD48 SPC AC 110900 Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0400 AM CDT Tue Apr 11 2023 Valid 141200Z - 191200Z ....DISCUSSION... Upper troughing is forecast to extend from the northern Rockies into northwest Mexico early D4/Friday. Surface pattern at the same time will likely feature a low in the central NE/KS border vicinity, with a dryline extending southward from this low through the eastern TX Panhandle and a cold front extending northeastward into western MN. Low-level moisture is expected to advect northward from central TX through the Ozarks and Lower MO Valley as a low-amplitude shortwave trough ejects through the central and southern High Plains and the surface low and dryline move east. The airmass is expected to destabilize ahead of the dryline, and the combination of large-scale ascent attendant the approaching shortwave and mesoscale ascent along the dryline will likely result in thunderstorm development. Steep mid-level lapses and moderate shear support the potential for severe thunderstorms capable of all hazards. Additional thunderstorms, some potentially strong to severe, are anticipated across western MO, eastern KS and central/eastern OK later D4/Friday night into D5/Saturday morning along the cold front as it surges southeastward. This front is expected to continue eastward/southeastward on D5/Saturday, pushing through the East/Southeast TX, Mid/Lower MS Valley, Lower OH Valley, and TN Valley on D5/Saturday. Thunderstorms are likely along the length of this front, with some severe possible. However, with the primary surface low displaced north over the Upper Midwest and Upper Great Lakes, low-level winds will likely veer ahead of the front. Additionally, the stronger mid-level flow will lag behind the front. This should limit the strength of the deep-layer vertical shear. Generally moderate buoyancy is anticipated as well. These factors are currently expected to limit the severe potential, precluding the need for an outlook area. Thunderstorms are possible over the Upper OH Valley and Mid-Atlantic along this front on D6/Sunday as it continues eastward. However, the quality of the low-level moisture (and resulting buoyancy) ahead of the front as well as the timing of the front remain uncertain, limiting predictability. Severe potential appears low on D7/Monday, given the moisture scouring from the previous frontal passage. Low-level moisture may begin returning on D8/Tuesday ahead of a low-latitude shortwave trough. ...Mosier.. 04/11/2023 = = = 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) .