Mesoscale Discussion 0314
   NWS Storm Prediction Center Norman OK
   0345 PM CDT Wed Apr 08 2020

   Areas affected...portions of southeastern MO...southern IL...far
   western KY and far southwest IN

   Concerning...Severe potential...Watch likely 

   Valid 082045Z - 082245Z

   Probability of Watch Issuance...95 percent

   SUMMARY...The severe thunderstorm threat is increasing across
   southeast MO, southern IL into adjacent portions of far western
   KY/southwest IN. Very large hail and damaging wind gusts will be the
   main concern with this activity, though a couple of tornadoes cannot
   be ruled out.

   DISCUSSION...A CU field over southeast MO continues to deepen late
   this afternoon. Strong heating has allowed temperatures to warm into
   the low and mid 80s F. South/southwesterly low level flow will
   continue to increase moisture across the MS/OH Valley region into
   this evening, with several areas already recording dewpoints in the
   mid 60s across far southeast MO into far western KY. This has
   resulted in moderate to strong destabilization, with MLCAPE values
   as high as 2500 J/kg apparent in 20z mesoanalysis. Forcing across
   the region is currently weak, and TCU development mainly driven by
   diurnal processes in the presence of moderate instability. However,
   stronger height falls and increasing upper level support will
   impinge on the area in the next few hours, and thunderstorm
   development is likely by 22z. 

   Initially, semi-discrete cells are expected with stronger vertical
   shear and very steep lapse rates (8-9 C/km) favoring supercells
   capable of very large hail and damaging wind gusts. With time, and
   as frontal forcing increases through the evening, upscale growth is
   expected with time as convection shifts east into southern IL and
   adjacent portions of far western KY/southwest IN, increasing
   potential for damaging winds. While low level moisture is expected
   to increase through the evening, boundary layer mixing will
   initially result in higher-based convection, limiting tornado
   potential. Nevertheless, a couple of tornadoes cannot be ruled out
   where richer low level moisture exists.

   ..Leitman/Guyer.. 04/08/2020

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

   ATTN...WFO...PAH...ILX...MEG...LSX...LZK...SGF...

   LAT...LON   38438784 37808789 36908863 36508951 36459022 36469111
               36789153 37619182 37999176 38189147 38289012 38528854
               38588801 38438784