Subj : DAY1SVR: Day 1 Convective To : All From : Mike Powell Date : Wed May 31 2023 15:37:00 ACUS01 KWNS 312002 SWODY1 SPC AC 312000 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Wed May 31 2023 Valid 312000Z - 011200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE SOUTHERN HIGH PLAINS... ....SUMMARY... Large hail, severe wind gusts, and a couple tornadoes are possible later this afternoon and evening over portions of the southern High Plains including eastern New Mexico and west/northwest Texas. ....20Z Update... The northwestern portion of the Slight Risk was trimmed slightly across northeast NM, where relatively cool and stable conditions are noted in the wake of ongoing convection. Otherwise, no changes have been made to the risk areas across the southern High Plains. See MCD 908 and the previous discussion below for more information regarding the severe threat in that area. A Marginal Risk has been added across northwest IA into southwest MN and adjacent portions of northeast SD/southeast ND, in conjunction with an MCV moving across the region. Modestly organized storms capable of isolated hail and localized downbursts will remain possible through the rest of the afternoon. See MCD 907 for more information. Elsewhere, no changes have been made. See MCD 909 for more information regarding the short-term threat in southeast CO/southwest KS, and the previous discussion below for more information elsewhere. ...Dean.. 05/31/2023 ..PREV DISCUSSION... /ISSUED 1132 AM CDT Wed May 31 2023/ ....Southern High Plains... Severe-thunderstorm potential will be maximized across the region later this afternoon into evening, with large hail, severe-caliber wind gust and tornado risks. An MCS continues to decay at late morning near the western Oklahoma/Texas Panhandle vicinity, with lingering cold pool influences across the OK/TX Panhandles. Meanwhile, scattered thunderstorms have become increasing prevalent across east-central/northeast Mexico this morning, seemingly related to a weak/lead mid-level impulse preceding the upper low centered near the Lower Colorado River Valley. The aforementioned ongoing early day convection across eastern New Mexico casts some uncertainty for later today. However, the south/southwest fringes of this stronger/more sustained convection should be favored areas for more robust/semi-discrete development later today, including in vicinity of modifying outflow and near higher terrain of east-central New Mexico. This should provide a net peak focus for areas along/south of I-40 this afternoon across east-central New Mexico, and into nearby west Texas/Texas South Plains by early evening. This will include initial semi-discrete supercells capable of large hail, including potentially significant hailstones (2+ inch diameter). This is where buoyancy is likely to be maximized with 35-45 kt effective shear. Some tornado potential will exist as well, particularly in vicinity of remnant/modifying outflow. Storm mergers and gradual upscale growth with some increase in severe-caliber wind potential should occur this evening eastward toward the New Mexico/Texas border region into the Texas South Plains vicinity and parts of the Texas Panhandle. ....Central High Plains... Isolated to locally scattered thunderstorms are still expected to form this afternoon near the dryline/lee trough and on higher terrain features, such as the Black Hills and Rockies foothills. Ample heating, steep lapse rates and 40s/50s F dewpoints will support upwards of 1000-2000 J/kg MLCAPE this afternoon. Mid/high-level winds will be relatively weak with a multicellular mode prevalent. Relatively isolated instances of large hail and severe-caliber wind gusts can be expected, particularly late this afternoon through early/mid-evening. $$ --- SBBSecho 3.14-Linux * Origin: Ilink: CCO - capitolcityonline.net (454:1/105) .