ZCZC SPCSWOMCD ALL ACUS11 KWNS 271241 SPC MCD 271241 VAZ000-TNZ000-KYZ000-271445- Mesoscale Discussion 0276 NWS Storm Prediction Center Norman OK 0741 AM CDT Sat Mar 27 2021 Areas affected...Much of middle and eastern Tennessee into parts of southeastern Kentucky and southwestern Virginia Concerning...Severe potential...Watch possible Valid 271241Z - 271445Z Probability of Watch Issuance...40 percent SUMMARY...An evolving cluster of thunderstorms will continue spreading across the Tennessee Valley toward the Cumberland Plateau through 11 AM to Noon EDT, with some potential to organize further and begin producing strong to perhaps occasionally severe wind gusts. It is not yet certain that a severe weather watch will be needed, but trends will continue to be monitored for this possibility. DISCUSSION...Consolidation and upscale growth of vigorous thunderstorm development continues across parts of the Mid South into Tennessee Valley region. This is being supported by large-scale ascent associated with lower/mid tropospheric warm advection, beneath a zone of enhanced divergence aloft, which is forecast to continue spreading across the Tennessee Valley into the Cumberland Plateau through 15-16Z. This convection includes at least one area of increasing organization, with a possible evolving broad mesoscale cyclonic circulation near Nashville. This still appears rooted above at least a shallow near-surface, potentially cool/stable layer, but mid 60s+ F surface dew points have been surging toward the southern Tennessee state border area the past few hours. Although cloud cover appears likely to slow boundary-layer insolation ahead of activity, it is possible that thermal advection and moistening could contribute to increasing boundary-layer instability as far north as the Interstate 40 corridor of eastern Tennessee within the next few hours. If this occurs, a corridor with potential for strong to severe wind gusts could begin to develop by mid to late morning, in the presence of sheared, 30-50+ kt southwesterly to west-southwesterly flow in the 850-500 mb layer. ..Kerr/Guyer.. 03/27/2021 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...MRX...JKL...LMK...OHX...HUN... LAT...LON 35758667 36748557 37188336 35908335 35568479 35158683 35158762 35758667 NNNN