BBS: TELESC.NET.BR Assunto: DAY2SVR: Nws Storm Prediction Center Norman Ok De: COD Weather Processor Data: Thu, 21 May 2026 17:22:41 +0000 ----------------------------------------------------------- ACUS02 KWNS 211722 SWODY2 SPC AC 211720 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1220 PM CDT Thu May 21 2026 Valid 221200Z - 231200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ... ...SUMMARY... Scattered severe storms capable of large hail and damaging winds are possible across western parts of Texas and Oklahoma. An isolated hail threat may extend into central Kansas, with sporadic occurrences of damaging wind and perhaps a few brief tornadoes from the central Gulf Coast into the Tennessee and Ohio Valleys. ...Synopsis... A short-wave trough over the northern and central High Plains Friday morning will become negatively tilted while translating through the upper MS Valley, ahead of a weaker, upstream disturbance moving through the central Rockies into central High Plains. Meanwhile, a series of lower-latitude disturbances will progress from the southern Plains and lower MS Valley into the TN and OH Valleys. At the surface, an area of low pressure will track from SD into northwest MN with a trailing cold front advancing east/southeast through the central Plains, and south into the southern High Plains where it will link with a secondary low pressure. A dryline is expected to sharpen through the afternoon from the intersection of the cold front in the vicinity of the TX South Plains into the Edwards Plateau. Elsewhere, a surface low is forecast to develop from western TN into IN/OH with an associated warm front lifting north into the OH Valley. ...Central and Southern Plains... An axis of 50s to low 60s dewpoints is expected to reside ahead of the cold front and dryline, with the steepest mid-level lapse rates confined to the southern High Plains portion of the warm sector. Resultant MLCAPE of 1500-2500 J/kg is forecast over western TX into the southern Panhandle, with instability decreasing with northeastward extent across KS and NE. Showers and thunderstorms are expected to develop early in the day along the front in NE with additional storms forming southwestward along the boundary during the afternoon from central KS into the southern TX Panhandle or TX South Plains, with more isolated development possible south along the dryline. Additional storms are possible in the immediate post-frontal environment in northeast NE. The most favorable overlap of moderate instability and around 30 kt of deep-layer shear is expected to reside over parts of western TX and the Panhandle where the potential will exist for supercell storm modes with the predominant hazard being large hail. Storms may tend to grow upscale into an MCS with a wind and hail threat spreading into parts of western OK and northwest TX Friday evening. Lesser-organized multicell structures appear possible from central KS into southeast NE. The best potential for marginally severe hail is expected over central KS where comparably (to NE) stronger instability will develop. ...Central Gulf Coast and Southeast into Ohio Valley... Some enhancement of the mid-level wind field will occur in association with the disturbances mentioned in the synopsis. Of potentially greater importance to severe-weather potential is the presence of a 25-40 kt low-level jet, which will persist through the day from the central Gulf Coast north toward the OH River amidst a moist and marginally to moderately unstable air mass with afternoon MLCAPE of 500-1500+ J/kg. Scattered to numerous thunderstorms are expected within the northward-expanding warm sector, with the strongest instability confined to cloud-free areas where greater daytime heating can occur. Embedded strong to severe storms will be most probable in those areas, and given the presence of 30-35 kt deep-layer shear, some potential for storm organization will exist, despite the existence of poor mid-level lapse rates. A corridor of stronger low-level shear (i.e., effective SRH of 100-200 m2/s2) is forecast from eastern MS and western AL through middle TN into OH, along the low-level jet axis, where a few brief tornadoes appear possible. Otherwise, locally damaging downburst winds appear to be the primary hazard. ..Mead.. 05/21/2026 $$ = = = 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 3.28-Linux * Origin: Capitol City Online (1:2320/107) ----------------------------------------------------------- [Voltar]