Weather Discussion #1789
A threat for damaging wind, isolated hail, and perhaps a tornado or two will spread southeastward through the evening. Eventual downstream watch issuance is likely
A storm cluster with embedded supercells is moving southeastward across eastern TN and western NC as of 22 UTC. A cell near the TN/NC border has recently produced an apparent tornado with a TDS, while other cells have produced occasional reports of wind damage and isolated hail. This storm cluster is expected to spread southeastward ahead of a surface wave currently near the KY/TN/VA border region. The downstream environment remains favorable for supercells, with a warm and very moist boundary layer, MLCAPE of 2000-3500 J/kg, and increasing deep-layer shear within the northwesterly flow regime, oriented orthogonal to the cold front moving across the region. Some upscale growth and an increase in damaging-wind potential is possible with time, though the favorable wind profiles will continue to support embedded supercells, with a threat of isolated hail. With the rich boundary-layer moisture and at least modest low-level hodograph curvature (as noted in recent VWPs from KMRX), some tornado threat could persist into the evening, with both persistent supercells, and with any line-embedded circulations if upscale growth occurs. With the severe threat expected to spread south of WW 526, eventual downstream watch issuance is likely. ..Dean/Smith.. 07/28/2026