Storm Prediction Center Mesoscale Discussion 2039

   Mesoscale Discussion 2039
   NWS Storm Prediction Center Norman OK
   1226 PM CDT Wed Aug 19 2026

   Areas affected...parts of south central/southeastern Nebraska
   adjacent southwestern Iowa and northwestern Missouri

   Concerning...Severe Thunderstorm Watch 599...

   Valid 191726Z - 191930Z

   The severe weather threat for Severe Thunderstorm Watch 599
   continues.

   SUMMARY...The ongoing cluster of storms may continue to become less
   organized and weaken, but strong thunderstorm development posing a
   risk for severe hail and wind may continue into the 2-4 PM CDT time
   frame.

   DISCUSSION...A broader cyclonic vortex has evolved from an initial
   supercell structure over the past couple of hours, with stronger
   associated thunderstorm development maintaining a modest
   south-southeastward propagation.  Subsequent evolution of this
   cluster remains uncertain, as latest Rapid Refresh continues to
   indicate weakening of initial lower/mid-tropospheric warm advection
   supporting forcing for ascent over the next couple of hours.  As
   this occurs, increasing mid-level inhibition and less unstable
   inflow may contribute to diminishing convection on the
   south/southwestern flank of the cluster.

   A corridor of stronger destabilization (including CAPE on the order
   of 1500-2000 J/kg) has evolved downstream of the ongoing cluster,
   near/southwest of Omaha and south of I-80 into southwestern Iowa. 
   This appears focused near the northern periphery of the elevated
   mixed-layer, as roughly depicted by the thermal gradient around 700
   mb.  This may shift southward a bit with continuing progression of
   the MCV within west-northwesterly mean flow, with forcing associated
   with the MCV and/or, perhaps, the associated surface cold pool
   supporting renewed convective development through 19-21Z.

   ..Kerr.. 08/19/2026

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

   ATTN...WFO...DMX...EAX...OAX...GID...

   LAT...LON   41289685 41239601 41189518 40689480 40109513 40089624
               40109685 40339771 40459825 40729884 41169887 41039817
               41289685 

   MOST PROBABLE PEAK WIND GUST...55-70 MPH
   MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN