Categorical Graphic Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area SLIGHT 84,076 11,663,388 Chicago, IL...Aurora, IL...Naperville, IL...Joliet, IL...South Bend, IN... MARGINAL 344,755 29,744,641 Indianapolis, IN...Milwaukee, WI...Nashville, TN...St. Louis, MO...Cincinnati, OH... Probabilistic Tornado Graphic Probability of a tornado within 25 miles of a point. Hatched Area: 10% or greater probability of EF2 - EF5 tornadoes within 25 miles of a point.
