Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Thu May 04 2023 17:31:10 ACUS02 KWNS 041731 SWODY2 SPC AC 041729 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1229 PM CDT Thu May 04 2023 Valid 051200Z - 061200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS CENTRAL TEXAS... ....SUMMARY... Severe thunderstorms will be possible across parts of central Texas Friday afternoon and evening, with large hail and damaging winds expected to be the primary threats. Isolated strong storms are also possible across portions of the Tennessee Valley to the central Gulf Coast, and across parts of Nebraska. ....Synopsis... An upper ridge will spread east from the south-central U.S. toward the Midwest/Southeast vicinity on Friday. As this occurs, an upper trough over the western U.S. will pivot northeast toward the northern/central Plains. Several shortwave impulses embedded within the upper ridge, as well as the ejecting western trough, will focus severe potential across portions of the southern Plains, the South and the central Plains. ....TX/far southeast OK... Central/eastern TX will remain well south/east of the influence for the ejecting western upper trough. However, forecast guidance depicts a favorably timed shortwave trough ejecting from Mexico toward the ArkLaTex during the afternoon. Moderate to strong destabilization is expected amid a seasonally moist airmass to the east of a dryline. Deep-layer flow will remain somewhat weak, but vertically veering profiles will contribute to 40+ kt effective shear magnitudes. Very steep midlevel lapse rates and elongated hodographs suggest potential for supercells capable of very large hail (some greater than 2+ inches). Steep low-level lapse rates and some midlevel dryness could also support strong downdrafts and severe outflow winds. ....MS/AL vicinity... A somewhat complicated/low-confidence forecast scenario is expected across parts of the Mid-South to the TN Valley/central Gulf Coast vicinity. An MCS may be ongoing at the beginning of the period somewhere in the vicinity of AR near the Mississippi River. Low-level moisture will be increasing through the morning and into the afternoon across the Lower MS Valley into parts of western/southern AL. The MCS may develop east/southeast along the moisture/instability gradient, or new development along outflow also could develop and track southeast during the afternoon. While convective evolution is uncertain, moderate vertical shear and at least weak instability will support strong gusts and hail. A secondary shortwave impulse is forecast to move across the TN Valley late in the period. This could aid in the development of elevated thunderstorms overnight into early Saturday morning across parts of the TN Valley. This activity would mainly pose a risk of marginally severe hail. ....Central Plains... Modest low-level moistening to the north/northeast of a surface low across the central High Plains will result in weak to locally moderate destabilization across much of NE during the afternoon/evening. A shortwave trough moving northeastward from the southern Rockies will provide forcing for ascent and thunderstorm development is expected by mid to late afternoon. Some upscale growth is possible by evening as a southerly low-level jet strengthens across the region. Isolated severe hail/wind will be possible with the strongest storms. ...Leitman.. 05/04/2023 $$ = = = 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) .