Mesoscale Discussion 1616
   NWS Storm Prediction Center Norman OK
   0256 PM CDT Fri Aug 28 2020

   Areas affected...Southern and eastern Iowa...far southwest
   Wisconsin...far northern Missouri...and far northwest Illinois

   Concerning...Severe potential...Severe Thunderstorm Watch likely 

   Valid 281956Z - 282100Z

   Probability of Watch Issuance...80 percent

   SUMMARY...A few severe storms are expected along a cold front this
   afternoon and evening. Large hail and damaging winds will be the
   primary threats.

   DISCUSSION...A cold front is moving southeastward across Iowa.
   Temperatures ahead of this front are in the low to mid 90s with
   dewpoints in the upper 60s to near 70. This has yielded 1000 to 1500
   J/kg MLCAPE. Latest SPC mesoanalysis shows MLCIN has eroded along
   most of the front, and storms have started to form north of Des
   Moines in the last 20 minutes. Expect additional development along
   the front from far southwest Wisconsin to far western Iowa where
   convergence starts to weaken. The DMX VWP shows around 35 to 40 kts
   of mid-level flow which will provide sufficient effective wind shear
   for storm organization and the potential for a few rotating
   updrafts. The 18Z DVN RAOB showed weaker shear around 25 kts, but
   mid-level flow will be strengthening through the afternoon, and thus
   wind shear should be increasing in eastern Iowa. Considering the
   potential for supercells and the moderate mid-level lapse rates
   around 7 C/km per KDVN 18Z RAOB, these storms may be capable of
   producing some large hail. In addition, some damaging winds may also
   occur.

   ..Bentley/Grams.. 08/28/2020

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

   ATTN...WFO...LOT...ILX...MKX...LSX...DVN...ARX...DMX...EAX...
   OAX...

   LAT...LON   41809591 42139427 42489302 43449111 43468993 42448938
               41099040 40319142 39999261 40049386 40689491 41809591