Mesoscale Discussion 1949 NWS Storm Prediction Center Norman OK 0904 AM CDT Wed Aug 12 2026 Areas affected...northern and central Illinois into western Indiana Concerning...Severe Thunderstorm Watch 574... Valid 121404Z - 121600Z The severe weather threat for Severe Thunderstorm Watch 574 continues. The severe weather threat may develop east of the watch area by 1530Z, likely requiring a new severe thunderstorm watch. Extrapolation of the current motion takes it to the eastern edge of the watch by 1530Z, likely requiring an additional watch. LAT...LON 41909007 41758803 41268700 40498663 40088648 39578665 39578722 39588774 39848855 40268968 40819028 41499046 41909007 MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 90 MPH MOST PROBABLE PEAK WIND GUST...65-80 MPH MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN