Mesoscale Discussion 2039
   NWS Storm Prediction Center Norman OK
   0551 PM CDT Sun Sep 29 2019

   Areas affected...east-central Illinois and west-central Indiana

   Concerning...Severe potential...Watch unlikely 

   Valid 292251Z - 292345Z

   Probability of Watch Issuance...20 percent

   SUMMARY...A localized severe threat continues along a warm front in
   the region.  Hail, damaging wind gusts, and an isolated tornado are
   the main threats.  A WW issuance is not anticipated for this
   activity.

   DISCUSSION...Lift associated with a mid-level shortwave trough
   centered over eastern Iowa and weak to moderate instability along a
   surface warm front has resulted in a cluster of multicell/supercell
   storms.  One of these storms has exhibited strong, yet brief,
   low-level rotation as it traversed the warm front near Mason County,
   Illinois.  These storms continue on their eastern trek in the
   vicinity of the warm front and continue with mid-level rotation and
   signatures consistent with large hail.  

   The downstream airmass suggests that this focused, yet isolated
   severe threat should continue with eastward extent and potentially
   reach west-central Indiana through sunset.  Thereafter, boundary
   layer cooling should result in a lessened severe risk.  The brief
   and localized window for this severe risk should preclude a WW
   issuance.

   ..Cook/Guyer.. 09/29/2019

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

   ATTN...WFO...IND...LOT...ILX...

   LAT...LON   40408710 40528837 40368908 39968912 39648859 39468743
               39488671 39728661 40118677 40408710