Mesoscale Discussion 1970
   NWS Storm Prediction Center Norman OK
   0604 PM CDT Thu Sep 12 2019

   Areas affected...eastern Iowa...southwest Wisconsin...northern
   Illinois

   Concerning...Tornado Watch 648...650...

   Valid 122304Z - 130100Z

   The severe weather threat for Tornado Watch 648, 650 continues.

   SUMMARY...The threat for an isolated tornado continues from
   northeast Iowa into southwest Wisconsin. A damaging wind threat may
   eventually develop southward across the remainder of eastern Iowa
   and into northern Illinois, and additional watches may be needed.

   DISCUSSION...Embedded supercells continue within an area of warm
   advection precipitation from northeast IA into southwest WI near a
   warm front. Although temperatures are currently cooler over WI,
   southwestern parts of the state are in close proximity to higher
   theta-e air just to the southwest. In addition, 850 mb winds will
   continue to provide advection and low-level shear. 

   To the south of the ongoing cluster, strong instability remains
   ahead of the cold front which is now over central IA. Over the next
   few hours, storms are expected to increase in coverage, with hail or
   wind possible. A brief tornado cannot be ruled out as effective SRH
   remains in the 150-250 m2/s2 range over northern IL.

   ..Jewell.. 09/12/2019

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

   ATTN...WFO...LOT...ILX...MKX...DVN...ARX...

   LAT...LON   41338769 40878919 40729013 40759072 40919128 41189165
               41509175 42099155 42499136 43379124 43789076 43769027
               43458981 43118918 42888872 42598806 42428771 42078746
               41648751 41338769