April 1996 tornado outbreak sequence

The April 1996 tornado outbreak sequence was a series of tornado outbreaks that occurred over a three-day period between April 19 to April 21, 1996 across a large area of eastern North America. It was the most notable outbreak of the year; the 19th was the most prolific tornado outbreak in Illinois history.

Thirty-three tornadoes hit Illinois. It broke the old record of 25 set on August 10, 1974. This outbreak can also be compared to the May 2004 tornado outbreak sequence as it was a very huge, deep and vigorous system. The same system produced tornadoes in Ontario on the 20th; and destructive tornadoes also occurred in Arkansas and Texas on the 21st.

The outbreak occurred when the warm front of a deep storm system moved north and east out of Missouri. April 19 started off cool and skies were overcast ahead of the warm front. Meteorologists were trying to figure out if the warm front would move into Illinois that afternoon. As the day wore on, temperatures warmed, dew points rose, and thunderstorms started to explode in Iowa during the mid-afternoon hours. Although there were some doubts on specifics, the potential significance of the outbreak was rather foreseeable, with storm chasers traveling from the Great Plains and the Storm Prediction Center issuing a high risk early on.

The outbreak across the south-central U.S. on the 21st was produced by a different weather system.

Thirty-three tornadoes hit Illinois and spread west and south into Missouri, and Iowa and east and north into Wisconsin, Michigan, and Indiana on Friday, April 19. The town of Decatur was hit by a large F3 tornado, as were the towns of Urbana and Ogden. Major damage and injuries occurred in all three locations, and one person was killed in Ogden.

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