Storm Prediction Center Mesoscale Discussion 1346

   Mesoscale Discussion 1346
   NWS Storm Prediction Center Norman OK
   1244 PM CDT Wed Jun 18 2025

   Areas affected...eastern IL and western/northern IN

   Concerning...Tornado Watch 432...434...

   Valid 181744Z - 181945Z

   The severe weather threat for Tornado Watch 432, 434 continues.

   SUMMARY...Tornado and damaging wind potential should increase into
   late afternoon amid multiple bands of thunderstorms spreading
   east-northeast from Illinois into Indiana. A strong tornado is
   possible.

   DISCUSSION...Primary midday tornado potential has been prominent
   near the immediate MCV/surface cyclone in west-central IL, including
   a damaging tornado in Morgan County, IL during the past hour.
   Enhanced surface vorticity within this persistent pocket of
   lower-topped storms should continue to pose a tornado threat across
   central IL. 

   An expanding arc of broken to linear convection into east-central IL
   should have increasing tornado/damaging wind potential as it spreads
   into IN through late afternoon. Area VWPs have been a bit subdued on
   0-1 km shear, but the PAH/VWX VWPs has gradually strengthened and
   this should spread north-northeast across the Wabash Valley. Tornado
   potential may be relatively maximized with 1) discrete, sustained
   supercells on the southern portion of the broader convective band
   and 2) in the more bent-back arc across northeast IL/northern IN
   with hybrid supercell/QLCS mesovortices.

   ..Grams.. 06/18/2025

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

   ATTN...WFO...IWX...IND...PAH...LOT...ILX...

   LAT...LON   40088992 40828884 41238803 41548731 41818666 41668587
               40658592 39758631 38548743 37878793 37788874 38858849
               38978843 39668950 40088992 

   MOST PROBABLE PEAK TORNADO INTENSITY...120-150 MPH
   MOST PROBABLE PEAK WIND GUST...65-80 MPH
   MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN