Mesoscale Discussion 0542
   NWS Storm Prediction Center Norman OK
   0222 PM CDT Tue May 05 2020

   Areas affected...Portions of far eastern TN...northern GA/SC...and
   western/central NC

   Concerning...Severe potential...Watch possible 

   Valid 051922Z - 052115Z

   Probability of Watch Issuance...60 percent

   SUMMARY...An increasing severe risk is expected this afternoon.
   Isolated large hail, damaging winds, and perhaps a couple tornadoes
   may occur. Watch issuance is possible.

   DISCUSSION...At the surface, veered southwesterly flow ahead of an
   eastward-moving cold front currently across middle TN and northern
   AL has limited low-level convergence along its length so far this
   afternoon. As a weak surface low continues to develop over the
   central Appalachians this afternoon and evening, its associated cold
   front will intersect an increasingly unstable airmass across eastern
   TN and northern GA. Orographic lift across the higher terrain of
   eastern TN and western NC in tandem with the cold front should aid
   in additional storm development across this region by 20-22Z.

   Across the Carolinas, a surface wedge front has moved little so far
   today. Some breaks in the low/mid-level clouds have recently
   occurred over this region, with heating now occurring to the north
   of this boundary across parts of western/central NC. Current
   expectations are for this boundary to make some northward progress
   as a warm front across NC through the remainder of the afternoon and
   into the early evening as the surface low continues to develop
   eastward. A moist and at least weakly unstable airmass is present
   ahead of the cold front and south of the wedge front. Steepened
   mid-level lapse rates of 7-8 C/km are also contributing to around
   500-1500 J/kg of MLCAPE, with localized potential for even stronger
   instability along/south of the front across the Carolinas later this
   afternoon and early evening.

   Any storms that form over the higher terrain of eastern TN/western
   NC/northern GA will have the potential to become severe as they move
   eastward, with 40-50 kt of effective bulk shear being supported by a
   belt of strong westerly mid-level flow preceding an upper trough
   over the Midwest/OH Valley. A semi-discrete supercell storm mode
   appears possible initially, with both a large hail and damaging wind
   risk. With time, upscale growth into a small bowing cluster may
   occur along the warm front in the Carolinas. If this occurs, then
   damaging winds would probably become the primary risk. A couple
   tornadoes also cannot be ruled out along the length of the boundary
   across the Carolinas, where backed low-level flow may locally
   enhance effective SRH.

   ..Gleason/Hart.. 05/05/2020

   ...Please see www.spc.noaa.gov for graphic product...

   ATTN...WFO...RAH...ILM...CAE...GSP...MRX...FFC...

   LAT...LON   34158275 34238492 34488539 35028544 35858399 36258277
               35948138 35728030 35517921 35167879 34777903 34297987
               34138098 34158275