Subj : DAY48SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sun Apr 30 2023 08:02:35 ACUS48 KWNS 300802 SWOD48 SPC AC 300801 Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0301 AM CDT Sun Apr 30 2023 Valid 031200Z - 081200Z ....DISCUSSION... A gradual uptick in severe-thunderstorm potential appears possible late this week and potentially into the weekend, as the upper-level pattern gradually deamplifies and allows for one or more shortwave troughs to potentially impinge on an increasingly unstable environment across the Great Plains. However, predictability remains relatively low regarding the details, and the stronger solutions are still only modestly favorable regarding low-level and deep-layer shear intensity. ....D4/Wednesday - Far West TX into the southern High Plains... A similar regime to D3/Tuesday is expected from far west TX into the southern High Plains on Wednesday, though some increase in buoyancy is possible, as modestly moist southeasterly low-level flow is maintained across the region. There is some indication that mid/upper-level flow may increase slightly as well, though predictability remains low in that regard. With favorably veered wind profiles, any increase in mid/upper-level wind speeds may result in sufficient deep-layer shear for organized multicells and perhaps a supercell or two. ....D5/Thursday - Southern/central Plains... Guidance generally agrees that a midlevel shortwave trough and associated jet maximum will emerge from the subtropical Pacific, in advance of the persistent West Coast longwave trough. This feature will move over portions of the southern and possibly central Plains, strengthening deep-layer shear across the region, along with the potential for organized convection. However, guidance also generally agrees that the surface cyclone development in the lee of the Rockies will be relatively weak, limiting the potential for northward moisture transport to some extent. Depending on the extent that stronger deep-layer flow/shear overlaps more favorable instability, some organized severe-thunderstorm threat appears possible Thursday afternoon and evening somewhere across the southern and/or central Plains. ....D6/Friday - D8/Sunday - Southern/central Plains into the lower MS Valley... Predictability regarding the evolution of the upper-level pattern begins to wane by the end of the week. In general, guidance suggests that the persistent upper-level trough over the western CONUS will finally eject eastward into the Great Plains, though likely in a notably weakened state. This may increase the potential for a favorable overlap of moderate-to-strong buoyancy and sufficient deep-layer shear somewhere across the central/southern Plains (and possibly into the lower MS Valley), though uncertainty remains high regarding the details of any such threat. ...Dean.. 04/30/2023 = = = 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) .