ZCZC SPCSWOMCD ALL ACUS11 KWNS 141548 SPC MCD 141548 NCZ000-SCZ000-GAZ000-141745- Mesoscale Discussion 0340 NWS Storm Prediction Center Norman OK 1048 AM CDT Sun Apr 14 2019 Areas affected...Piedmont of northeast Georgia...Carolina into Virginia Concerning...Severe potential...Watch possible Valid 141548Z - 141745Z Probability of Watch Issuance...60 percent SUMMARY...Widely scattered thunderstorm development is underway along and to the lee of the southern Appalachians. Trends are being monitored. However, while one or more tornado watches may be needed, current expectations are that this will be most probable in the 1-3 PM EDT (perhaps later) time frame. DISCUSSION...With the eastward progression of a significant large-scale trough, now over the Mississippi Valley, and a deepening surface cyclone migrating northeastward through the lower Ohio Valley, the large-scale environment appears in the process of becoming increasingly conducive to severe storm development to the lee of the southern Appalachians. The boundary layer has become seasonably moist with surface dew points generally in the upper 60s. However, mid-level lapse rates are fairly modest, and areas of mostly stratiform precipitation as well as mid/high cloudiness are at least slowing insolation. Mixed-layer CAPE is still somewhat modest (less than 1000 J/kg), though deep layer and low-level shear are already fairly strong, and strengthening. Most model output generally appears to suggest that the most substantive severe weather potential may not commence until sometime later this afternoon, gradually spreading northeastward across the piedmont, from northeast Georgia through North Carolina. This is expected to accompany the onset of stronger surface pressure falls and peak boundary layer destabilization, when probabilities for supercells with the risk for tornadoes and damaging wind gusts are expected to maximize. ..Kerr/Grams.. 04/14/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...RAH...RNK...CAE...GSP...FFC... LAT...LON 34408338 35918137 36538064 36307974 35637949 33508227 33068288 34408338 NNNN