ZCZC SPCSWOMCD ALL ACUS11 KWNS 191833 SPC MCD 191833 NCZ000-VAZ000-SCZ000-TNZ000-GAZ000-192030- Mesoscale Discussion 0494 NWS Storm Prediction Center Norman OK 0133 PM CDT Fri Apr 19 2024 Areas affected...portions of the Tennessee Valley into the Mid-Atlantic Concerning...Severe potential...Watch unlikely Valid 191833Z - 192030Z Probability of Watch Issuance...20 percent SUMMARY...Thunderstorm development is anticipated in the next couple of hours across parts of the southern Appalachians. These storms should gradually intensify through the mid/late afternoon, and may pose a severe hail/wind threat across parts of far eastern Tennessee and adjacent portions of Virginia and the Carolinas. The coverage of strong/severe storms should be sufficiently limited to preclude watch issuance. DISCUSSION...A gradually deepening cumulus field has been tracked in GOES visible/IR imagery and regional radars over the past 60 minutes. Lingering inhibition has precluded deeper convection so far, but continued daytime heating along with combined forcing for ascent along an approaching cold front and orographic lift within the southern Appalachians should foster more robust thunderstorms in the coming hours. Despite weak low-level winds, 30-40 knot flow aloft is supporting effective bulk shear values near 30-35 knots, which should be sufficient for some organization of deeper cells that may pose a large hail risk (most likely between 0.75 to 1.25 inch in diameter). Additionally, heating of a somewhat dry air mass downstream across the Carolinas (where temperatures are climbing into the low 80s under clearing skies) should steepen low-level lapse rates by late afternoon to around 8 C/km. This may favor outflow-driven storms with a tendency for upscale growth into clusters and the potential for strong to severe gusts. ..Moore/Smith.. 04/19/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...RAH...RNK...RLX...CAE...GSP...MRX...FFC... LAT...LON 36658012 36187981 35217999 34728071 34498146 34518259 34618339 34908423 35268452 35668427 36978244 37068172 36968086 36658012 NNNN