Subj : DAY1SVR: Day 1 Convective To : All From : Mike Powell Date : Wed May 24 2023 15:59:00 ACUS01 KWNS 241943 SWODY1 SPC AC 241942 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0242 PM CDT Wed May 24 2023 Valid 242000Z - 251200Z ....THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF EASTERN NEW MEXICO AND INTO ADJACENT PORTIONS TEXAS PANHANDLE AND SOUTH PLAINS REGION... ....SUMMARY... Scattered severe thunderstorms are expected across the southern High Plains vicinity from 4 PM to Midnight CDT. A few intense supercells are anticipated and will be capable of very large hail. The threat for a few tornadoes should peak between 6 to 9 PM CDT and severe wind gusts between 8 to 11 PM CDT. ....Discussion... Expectations for evolution of the convective/severe risk -- as laid out in prior forecasts -- remain valid at this time, with strong/isolated severe storms occurring across portions of the Great Basin, and expected development of High Plains convection in the next 1 to 2 hours anticipated. The primary adjustment in this update has been to expand the MRGL risk area slightly in portions of Nevada/Utah, to more thoroughly corral the evolving hail/wind risk. ...Goss.. 05/24/2023 ..PREV DISCUSSION... /ISSUED 1128 AM CDT Wed May 24 2023/ ....Eastern NM and west TX... In the wake of an MCS last night, a residual outflow boundary extends northwest from central TX and has become more diffuse near the South Plains and east-central NM border area. Richer boundary-layer moisture has been displaced southwest of the outflow, with upper 50s to mid 60s surface dew points common across the Permian Basin and Lower Pecos Valley. There will be gradual advection of this moisture to the north-northwest along the eastern NM/northwest TX border area. With very steep mid-level lapse rates of 9-9.5 C/km sampled by the 12Z MAF/ABQ soundings, relatively large buoyancy for the High Plains is anticipated at peak heating with MLCAPE from 1500-3000 J/kg. Scattered thunderstorms are most likely to develop in the late afternoon to early evening in/off the Raton Mesa vicinity, with more isolated activity expected south across eastern NM into the Trans-Pecos. While some weakness in the hodograph is expected around 700 mb, greater low-level curvature and speed shear above 700 mb relative to the past few days will yield a more elongated and relatively straight mid-upper hodograph. This should yield several discrete splitting supercells. Given the rather favorable CAPE/lapse rate environment, very large hail and potential for a few tornadoes appear increasingly probable. Storm-scale interference and eventual amalgamation of supercells, along with an evening increase in the low-level jet, should result in upscale growth and an increasing threat for severe wind gusts during the latter half of the evening. A southeast-moving MCS should emanate from the southwest TX Panhandle and northwest TX region, likely tracking near the outflow boundary from last night's MCS before weakening overnight. ....Northern Great Basin to eastern MT... While a broad upper trough persists over the West, multiple embedded vorticity maxima will rotate north-northeast across the northern Great Basin to northern High Plains areas. These will aid in scattered to widespread thunderstorm development later this afternoon. Buoyancy will remain weak (except over eastern MT) and deep-layer shear will be relatively modest, especially with eastern extent. Sporadic strong to locally severe wind gusts should be the primary hazard, with a secondary threat for isolated marginally severe hail. ....South/central FL... A diffuse front across central FL, and local sea breeze boundaries/collisions farther south, will again support scattered thunderstorms this afternoon. The stronger surface heating and larger MLCAPE will be confined to along and south of the front. Relatively cool mid-level temperatures near -11 C at 500 mb per 12Z MFL/TBW soundings should compensate for weak/weakening upper flow. Isolated strong-severe outflow gusts and small to marginally severe hail will be possible in the more robust clusters. $$ --- SBBSecho 3.14-Linux * Origin: Ilink: CCO - capitolcityonline.net (454:1/105) .