ZCZC SPCSWOMCD ALL ACUS11 KWNS 172155 SPC MCD 172155 VAZ000-NCZ000-SCZ000-WVZ000-TNZ000-172300- Mesoscale Discussion 1548 NWS Storm Prediction Center Norman OK 0455 PM CDT Tue Aug 17 2021 Areas affected...Western Carolinas and southwest Virginia Concerning...Severe potential...Tornado Watch likely 444...445... Valid 172155Z - 172300Z Probability of Watch Issuance...95 percent SUMMARY...The threat for a few tornadoes is expected to persist this evening and overnight as Tropical depression Fred continues north. Replacement tornado watches are forthcoming. DISCUSSION...Latest track guidance from WPC placed the center of Tropical Depression Fred at 34.7N 83.9W, or about 90 miles WSW of Asheville, NC. Along Fred's southeastern flank, multiple bands and clusters of low-topped supercells have produced several reported tornadoes over the last couple of hours. As Fred continues northward across the western Carolinas, the environment is forecast to remain favorable for additional tornadoes this evening, and possibly overnight. SPC mesoanalysis and regional VAD wind profiles depict a corridor of strong low-level shear with 0-1km in excess of 200 m2/s2 from northwestern South Carolina to southwestern Virginia. While buoyancy is not overly strong, cloud breaks and tropical dewpoints near 75 F are supporting tall and skinny CAPE profiles with MLCAPE around 500-1000 J/kg. The combination of instability and low-level shear will continue to support a risk for mini-supercells with damaging wind gusts and tornadoes across the western Carolinas and southwestern Virginia this evening. A new Tornado Watch will be coordinated shortly ahead of the 23 UTC expiration of WW444 and WW445. ..Lyons/Thompson.. 08/17/2021 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...RAH...RNK...CAE...GSP...MRX... LAT...LON 35758252 36338193 36708139 37128110 37368080 37508029 37317971 36937939 36527941 35977960 35457986 35148011 34858042 34628069 34328095 33778173 33728212 33878227 34208230 34688245 35368264 35598270 35758252 NNNN