Mesoscale Discussion 1724
   NWS Storm Prediction Center Norman OK
   0801 PM CDT Tue Sep 29 2020

   Areas affected...Parts of coastal North Carolina and southeast
   Virginia

   Concerning...Severe potential...Watch unlikely 

   Valid 300101Z - 300300Z

   Probability of Watch Issuance...20 percent

   SUMMARY...At least some further increase in potential for locally
   damaging wind gusts, and perhaps a tornado or two, appears possible
   with an evolving squall line approaching North Carolina and
   southeastern Virginia coastal areas through 11 PM-1 AM EDT.  While
   it is not yet clear that a severe weather watch will be needed,
   trends will continue to be monitored for this possibility.

   DISCUSSION...As a significant mid-level short wave trough pivots
   into the central/southern Appalachians vicinity this evening, a
   surface low may gradually consolidate and deepen across southeastern
   Virginia, along a cold front approaching southern Mid Atlantic
   coastal areas.  Based on latest RAOB and VWP data, southerly flow
   around 850 mb may already be increasing near North Carolina coastal
   areas.  Through 03-05Z, further strengthening (to 50-60+ kt) is
   forecast across the North Carolina Outer Banks into the vicinity of
   southeastern Virginia coastal areas. 

   Model forecast soundings indicate that this will contribute to
   enlarging, clockwise-curved low-level hodographs in the warm, moist
   sector characterized by lower/mid 70s surface dew points, as a
   frontal convective band overspreads the region.  This band has been
   generally shallow and weak, with little lightning, largely due to
   relatively warm mid-levels with weak lapse rates limiting
   boundary-layer CAPE.  

   While instability is not likely to improve much through the evening,
   it is possible that strengthening low-level shear could contribute
   to increasingly organized convection, with occasionally
   strengthening low-level mesocyclones.  These may be accompanied by
   at least somewhat greater potential for damaging surface gusts, and
   perhaps a couple of tornadoes, than has existed the past few hours.

   ..Kerr/Hart.. 09/30/2020

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

   ATTN...WFO...AKQ...MHX...

   LAT...LON   35247752 35997717 37027680 37787580 36847571 35347556
               34227742 35247752