Mesoscale Discussion 0837
   NWS Storm Prediction Center Norman OK
   0417 AM CDT Fri Jun 05 2020

   Areas affected...portions of central and eastern IA

   Concerning...Severe Thunderstorm Watch 256...

   Valid 050917Z - 051045Z

   The severe weather threat for Severe Thunderstorm Watch 256
   continues.

   SUMMARY...Severe storms capable of damaging winds appear most likely
   from near Des Moines into south-central IA over the next couple of
   hours. Local watch extension may be needed if trends continue.

   DISCUSSION...A supercell on the southern end of a line of convection
   tracking southeast across IA will pose the greatest severe threat
   over the next couple of hours as it tracks toward Des Moines and
   south-central IA. Radar presentation of this cell has shown
   impressive rotation at times with strong outflow winds. Recent
   reports of downed trees and power lines have been relayed via NWS
   DMX, and MRMS MESH indicates near 1 inch hail is possible. This
   storm is tracking southeast around 35-40 kt along a strong
   instability gradient amid effective shear values greater than 35 kt.
   The downstream environment should remain ideal for maintenance of
   this intense supercell and severe gusts are expected.

   Further east, convection has been struggling to maintain intensity
   over the last hour or so. This area is on the weaker side of the
   instability gradient and encountering greater inhibition.
   Nevertheless, strong to severe wind gusts will still be possible
   over the next 1-2 hours, despite expected longer-term weakening.

   ..Leitman.. 06/05/2020

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

   ATTN...WFO...DVN...ARX...DMX...

   LAT...LON   42209448 42749296 43059193 42519132 41499095 41019126
               40759197 40709312 40959389 41829472 42109469 42209448