Mesoscale Discussion 1261
   NWS Storm Prediction Center Norman OK
   1100 AM CDT Sat Jul 18 2020

   Areas affected...Southern WI...Northern IL

   Concerning...Severe potential...Watch unlikely 

   Valid 181600Z - 181800Z

   Probability of Watch Issuance...20 percent

   SUMMARY...Ongoing thunderstorm cluster could pose an isolated severe
   wind/hail risk into early this afternoon. WW issuance is currently
   considered unlikely.

   DISCUSSION...At 16Z, a persistent thunderstorm cluster is ongoing
   across southwest WI into northwest IL. While this system has been
   generally disorganized this morning, there has been some recent
   increase in updraft intensity along the leading edge, likely related
   to gradually increasing buoyancy and decreasing CINH downstream of
   this system. Effective shear of 25-35 kt is only marginally
   supportive of organized convection into southern WI/northern IL, but
   MLCAPE of 1500-2500 J/kg will support a threat of isolated large
   hail with the stronger updrafts. Some localized damaging wind is
   also possible, especially if a more substantial cold pool develops
   with time.

   Since this system is expected to remain on the fringe of the more
   favorable severe environment, watch issuance is unlikely, unless
   trends support evolution into a more organized forward-propagating
   MCS.

   ..Dean/Hart.. 07/18/2020

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

   ATTN...WFO...LOT...MKX...DVN...

   LAT...LON   43168960 43188886 43158830 43078810 42438813 42148825
               41898876 42028965 42399045 42659025 42899000 43168960