Mesoscale Discussion 0597
   NWS Storm Prediction Center Norman OK
   0320 PM CDT Sat Apr 30 2022

   Areas affected...Northern Illinois into southern Wisconsin.

   Concerning...Tornado Watch 163...

   Valid 302020Z - 302145Z

   The severe weather threat for Tornado Watch 163 continues.

   SUMMARY...The severe weather threat continues within watch 163.

   DISCUSSION...Storm strengthening has been a slow process this
   afternoon, but have started to show greater intensity over the past
   half an hour as cooling temperatures aloft overspread the region.
   There is uncertainty about the threat with the line of storms across
   north-central Illinois. These storms now show some broadly rotating
   updrafts within the line and have a reflectivity appearance
   indicating embedded supercell structures. However, these storms are
   approaching the northeastern extent of the best instability and are
   not that intense yet. They also seem to be moving northeast quicker
   than the warm front. This would likely cause storms to interact with
   the warm front over the next hour. This could lead to a locally
   enhanced tornado threat, but given the lack of more robust updrafts,
   the internal pressure perturbations and low-level stretching may not
   be significant enough to support a tornadic threat. 

   Farther west, a few storms are starting to form along a boundary
   across western Illinois. Winds ahead of this activity are more
   veered and thus, the tornado threat should me minimal, but
   temperatures aloft are cooler in this region and instability/shear 
   would support supercell structures. Therefore, damaging winds and
   large hail is possible from the storm currently forming in Knox
   county and any additional storms which develop along this boundary.