Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Jun 21 2023 17:31:54 ACUS02 KWNS 211731 SWODY2 SPC AC 211730 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Wed Jun 21 2023 Valid 221200Z - 231200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF SOUTHEAST WY...EASTERN CO...AND NORTHEAST NM... ....SUMMARY... Severe thunderstorms are possible on Thursday across parts of the central and southern High Plains, with a threat of large hail (possibly in excess of 2 inches in diameter), severe wind gusts, and a tornado or two. ....Synopsis... A seasonably deep upper trough is forecast to begin ejecting northeastward across the southwest CONUS on Friday. Farther east, a shortwave ridge will remain in place across parts of the southern Rockies/High Plains, while a mid/upper-level low will move little over the Southeast and Ohio Valley. An outflow-enhanced surface boundary is forecast to be draped somewhere from the VA Tidewater region southwestward toward the upper TX Coast, then northwestward toward the TX South Plains, and finally northward into the CO Front Range. ....Central/southern High Plains... Favorably moist post-frontal surface flow will again support scattered thunderstorm development across parts of the central/southern High Plains on Thursday. Initial development is expected from near the Raton Mesa vicinity in NM northward along the CO Front Range into southeast WY. Stronger deep-layer flow will remain west of the Rockies through the evening, but in the presence of moderate to locally strong buoyancy, veering wind profiles and 30-40 kt of effective shear will be sufficient for a few supercells. Large hail (possibly in excess of 2 inches in diameter) will be the primary initial hazard, though a tornado or two cannot be ruled out as well. Storm coverage through early evening is currently expected to be somewhat greater from southeast WY into eastern CO and northeast NM, with more isolated development farther south into the remainder of the southern High Plains. Upscale growth into one or more clusters will be possible with time Thursday evening, potentially resulting in a threat for at least isolated severe wind/hail spreading eastward into a larger portion of the High Plains, before diminishing instability with eastward extent results in a weakening trend overnight. ....Gulf Coast into parts of the Southeast... A remnant MCS may be ongoing somewhere near the upper TX or LA Gulf Coast at the start of the period, though most guidance suggests it will already be offshore by 12Z and move across the northern Gulf of Mexico during the day if it persists. If the system tracks farther north, or weakens quickly and allows the effective surface front to move northward, then some isolated severe threat may evolve near the Gulf Coast, but confidence remains too low for probabilities in this area. A more favorable area for at least isolated strong to severe storms may evolve from FL into south GA and parts of the Carolinas, where rich low-level moisture will support the development of moderate buoyancy along/south of the front, despite weak midlevel lapse rates. Modestly enhanced low/midlevel flow along the eastern periphery of the mid/upper-level low may support localized damaging gusts and perhaps a brief tornado will the strongest convection. Farther south across the FL Peninsula, low/midlevel flow will be somewhat weaker, but somewhat stronger buoyancy may support an isolated damaging wind and hail risk. ...Dean.. 06/21/2023 $$ = = = 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) .