Subj : DAY48SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Fri Apr 14 2023 09:03:46 ACUS48 KWNS 140903 SWOD48 SPC AC 140902 Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0402 AM CDT Fri Apr 14 2023 Valid 171200Z - 221200Z ....DISCUSSION... ....Monday/Day 4 and Tuesday/Day 5... From Monday into Tuesday, a shortwave trough is forecast to move across the Desert Southwest and into the southern Plains. Ahead of the shortwave, some low-level moisture is expected to return northward into parts of Texas and Oklahoma from Monday night into Tuesday. Isolated to scattered thunderstorms will be possible in parts of the southern Plains Tuesday afternoon. Any severe threat will likely depend upon how much moisture is available. At this time, model variance concerning moisture return is too great for confidence concerning the magnitude of any a severe threat. ....Wednesday/Day 6 to Friday/Day 8... On Wednesday, west-southwest mid-level flow is forecast to become established across much of the southwestern U.S. Moisture return will likely continue across the southern and central Plains, where model forecasts show 60+ surface dewpoints over the eastern half of Texas into eastern Oklahoma and southeast Kansas by late afternoon. Large-scale ascent is forecast to be primarily focused across the central Plains. In response, scattered thunderstorm development will be possible Wednesday afternoon and evening from eastern Kansas northward into the mid Missouri Valley. The greatest convective coverage appears likely to be during the evening into the overnight, along the nose of a low-level jet from eastern Kansas northward into the mid Missouri Valley. Isolated wind damage and hail will be possible with the stronger thunderstorms. The current thinking is that any substantial severe threat will remain localized, and in areas where more instability develops. On Thursday, a cyclonic mid-level pattern is forecast across much of the western and central U.S. The moist axis, along with a dryline, is forecast to be in place from northwest Texas into western Oklahoma and southern Kansas. Scattered thunderstorm will be possible to the east of the dryline during the afternoon and evening. Model forecast instability and deep-layer shear suggests that an isolated large hail and wind damage threat will be possible with supercells. Although there is some uncertainty as to the spacing of the severe threat, a 15 percent area has been added across parts of the southern and central Plains into the Ozarks, where the combination of moisture, instability and deep-layer shear is forecast to be the greatest. A severe threat could also develop on Friday ahead of a cold front moving through the Mississippi Valley. At this range, the model solutions move a mid-level jet into the central U.S., but have large differences concerning the placement of the moist axis. This introduces a large amount of uncertainty concerning the spacing of any severe threat. ...Broyles.. 04/14/2023 = = = 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) .