Mesoscale Discussion 0809
   NWS Storm Prediction Center Norman OK
   1209 PM CDT Sun May 26 2019

   Areas affected...Portions of the Ohio Valley

   Concerning...Severe potential...Watch possible 

   Valid 261709Z - 261845Z

   Probability of Watch Issuance...60 percent

   SUMMARY...Storm coverage is expected to increase across portions of
   the Ohio Valley this afternoon/evening ahead of MCV now located in
   southern Illinois. Severe wind and hail are the main threats and a
   severe thunderstorm watch issuance is possible.

   DISCUSSION...Storm coverage will increase across portions of the
   Ohio Valley this afternoon and evening. Visible satellite imagery
   shows a building Cu field across the region with a MCV and
   associated showers/thunderstorms in southern Illinois. Temperatures
   have warmed into the 80s with dewpoints in the mid 60s to low 70s
   helping to increase MLCAPE to 1000-1500 J/kg per mesoanalysis. A
   shortwave trough and increased mid-level flow will traverse over the
   Ohio Valley this afternoon/evening, helping to spread forcing for
   ascent and increasing shear over the region.

   Multi-cellular clusters and isolated supercells are likely to
   develop within this warm/moist/unstable environment. Given the
   warming boundary layer, low-level lapse rates will steepen and
   increase the potential for damaging wind gusts. Severe hail is also
   possible, but mid-level lapse rates are marginal. While thunderstorm
   coverage should increase, there is still some uncertainty regarding
   severe coverage and upscale organization that would increase the
   severe threat. However, severe thunderstorm coverage should be
   sufficient enough to warrant a severe thunderstorm watch.

   ..Nauslar/Thompson.. 05/26/2019

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

   ATTN...WFO...LWX...RNK...PBZ...RLX...MRX...JKL...ILN...LMK...
   IND...PAH...

   LAT...LON   38288718 38568700 38908634 39548474 39658386 39538140
               39498058 39427994 39157966 38447967 37807982 37248060
               37188117 36988219 37078239 36988304 37008425 37078506
               37148599 37148673 37218730 37598728 38288718