ZCZC SPCSWOMCD ALL ACUS11 KWNS 210046 SPC MCD 210046 TXZ000-210215- Mesoscale Discussion 0502 NWS Storm Prediction Center Norman OK 0746 PM CDT Sat Apr 20 2024 Areas affected...South-central into deep south TX Concerning...Severe potential...Watch possible Valid 210046Z - 210215Z Probability of Watch Issuance...40 percent SUMMARY...Isolated severe storms may evolve with time this evening, with a threat of large hail and localized severe gusts. DISCUSSION...Elevated convection has recently increased in coverage and intensity north of a cold front across western portions of south-central TX, with recent initiation noted farther south near a stationary front, north of Laredo. Confidence in greater storm coverage this evening is higher with northward extent, where elevated convection may continue to evolve within an environment characterized by MUCAPE of 1000-1500 J/kg (as noted in the 00Z DRT sounding) and sufficient effective shear for some storm organization. Isolated hail will be possible within this regime as storms spread eastward with time. Near-term storm potential farther south remains more uncertain, with generally nebulous large-scale ascent across the region, and some nocturnal cooling/stabilization expected with time. However, the environment south of the deeper post-frontal cold air is conditionally favorable for severe storms, with steep midlevel lapse rates atop rich low-level moisture supporting MLCAPE in excess of 2000 J/kg. If a supercell can evolve within this regime, there would be at least an isolated threat of large to very large hail (approaching 2 inches in diameter), along with some threat for severe gusts with convection that remains rooted closer to the surface. Watch issuance is possible, if supercell development within this more favorable environment appears imminent. ..Dean/Guyer.. 04/21/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...CRP...EWX...BRO... LAT...LON 28050022 28520043 29779985 29769811 28009808 27019871 26799929 27129981 28050022 NNNN