Fairdale Tornado a Rare EF4 For North-Central Illinois

A large tornado that heavily damaged the town of Fairdale, Illinois, on April 9, 2015 was of an intensity rarely witnessed in that part of north-central Illinois.

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The National Weather Service rated the Fairdale tornado as an EF4, with maximum winds up to 200 mph in the town of Fairdale. The tornado lasted 41 minutes over a path of 30.2 miles and was just over one-third of a mile wide, at its widest. 

This was the first F/EF4 or stronger tornado in the forecast area covered by the NWS-Chicago office in almost 25 years, since an F5 tornado struck Plainfield, Illinois, on August 28, 1990. 

According to the National Climatic Data Center, only three tornadoes of F/EF3 intensity or stronger on the Enhanced Fujita scale have occurred in Ogle, De Kalb or Boone counties in records dating to 1950.

These three counties form a rough semicircle southwest, southeast and east of the city of Rockford, Illinois.

Typical EF3 damage (estimated winds 136-165 mph) includes entire stories of well-constructed houses destroyed, severe damage to large buildings such as shopping malls, trees debarked, heavy cars lifted off the ground and thrown and structures with weak foundations blown away some distance.

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Chief among these few previous strong north-central Illinois tornadoes was an F4 tornado which tore through the city of Belvidere, Illinois on April 21, 1967.

This 1967 tornado first touched down only about 10 miles north of Fairdale, just outside the city of Rockford, then carved a 28-mile long path through the southeast side of Belvidere, destroying 127 homes and damaging hundreds more. Four hundred vehicles at the Chrysler assembly plant near Interstate 90 were destroyed, as well.

Of the 24 killed in that tornado, 13 were killed at Belvidere High School, where students were loading onto buses at the time. Another 300 were injured at the school. 

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The Belvidere tornado was just one of 45 tornadoes in five Midwestern states that day, killing 58 and injuring 1113. Two other F4 tornadoes touched down that day, both in the Chicagoland metro.

One F4 tore through Lake Zurich destroying 75 homes. The most deadly tornado of the day carved a 16-mile path through Chicago's near south side, including the suburb of Oak Lawn, killing 33.

The NWS-Romeoville office called it "Northern Illinois' Worst Tornado Disaster".

Interestingly, Chicagoland has had a history of violent (F/EF4+) tornadoes, besides the April 1967 outbreak.

An F4 tornado spawned during the infamous Palm Sunday Outbreak of April 11, 1965 in the far northwest suburb of Crystal Lake killed 6 and injured 75. F4 tornadoes also touched down just south of Waukegan in September 1972 and in the southwest suburb of Lemont in June 1976. 

One of the state's only two F/EF5 tornadoes on record touched down in the far southwest suburbs of Chicago on August 28, 1990, tearing through parts of Will and Kendall Counties, including the city of Plainfield. Twenty-nine were killed and another 350 were injured.

The last violent (EF4+) tornado in the state of Illinois prior to Fairdale happened during the November 17, 2013 outbreak in the city of Washington. 

Including Fairdale, there have been only 33 tornadoes of F/EF4 intensity or stronger from 1950-2015 in the state of Illinois, according to the NWS.

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