ZCZC SPCSWOMCD ALL ACUS11 KWNS 121937 SPC MCD 121937 VAZ000-NCZ000-WVZ000-TNZ000-122130- Mesoscale Discussion 0621 NWS Storm Prediction Center Norman OK 0237 PM CDT Sun May 12 2019 Areas affected...southern Virginia and northern North Carolina Concerning...Severe potential...Watch unlikely Valid 121937Z - 122130Z Probability of Watch Issuance...5 percent SUMMARY...A severe storm or two may evolve this afternoon across southwestern Virginia and vicinity, along with attendant risk for damaging wind gusts and marginal hail. Threat should remain too isolated to warrant WW consideration. DISCUSSION...Latest radar loop continues to show a very gradual uptick in convective intensity across the southwestern Virginia vicinity, near and just ahead of the slowly advancing surface cold front. As temperatures have warmed into the mid 70s, surface-based CAPE has reached 500 J/kg -- which has supported the deepening convection. As isolated storms develop over the next 1-2 hours, stronger updrafts will be aided by gradually increasing flow with height that is yielding 0-6km bulk shear near 50 kt -- though veered low-level flow is yielding rather weak shear in the 0-1 km layer. With these stronger cells, gusty/locally damaging winds and marginal hail will likely be a concern through peak heating, until storms begin to weaken diurnally. ..Goss/Grams.. 05/12/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...AKQ...LWX...RAH...RNK...MRX... LAT...LON 36908208 37568022 38127946 36877662 36457851 36288129 36908208 NNNN