Mesoscale Discussion 1733
   NWS Storm Prediction Center Norman OK
   0927 PM CDT Mon Jul 29 2024

   Areas affected...parts of southern Illinois...adjacent portions of
   Indiana and Kentucky

   Concerning...Severe Thunderstorm Watch 563...

   Valid 300227Z - 300430Z

   The severe weather threat for Severe Thunderstorm Watch 563
   continues.

   SUMMARY...Ongoing thunderstorms may gradually evolve into organizing
   southeastward propagating cluster with increasing risk for
   potentially damaging wind gusts through 11 PM-Midnight CDT.

   DISCUSSION...Storms initiating to the northeast through east of the
   Greater St. Louis area, have been supported by forcing for ascent
   associated with low-level warm advection, in the wake of mid-level
   troughing slowly digging through the upper Great Lakes/Ohio Valley. 
   This has been occurring within a very moist (including upper 70s
   surface dew points) and highly buoyant boundary layer, in the
   presence of at least modest clockwise curved hodographs, beneath
   30-40+ kt northwesterly flow in the 700-500 mb layer.  

   While a few supercell structures have evolved, with gradual
   decoupling of the boundary layer underway and flow closer to the
   surface (near and below 850 mb) forecast to remain more modest,
   tornadic potential seems likely to remain limited.  However, with
   some further upscale growth still probable through 04-05Z,
   increasing outflow, aided by evaporative cooling  within
   dry/potentially cool air in the lower/mid-troposphere and melting
   hail, may be accompanied by increasing potential for damaging
   surface gusts.

   ..Kerr.. 07/30/2024

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

   ATTN...WFO...IND...PAH...ILX...LSX...

   LAT...LON   38448874 38668808 38498750 37888723 37578843 38078912
               38548949 38448874