By John Dodge
CHICAGO (CBS) — For nearly 90 minutes, Walker Ashley followed the violent storms that pulverized northern Illinois on Thursday evening.
One tornado flattened the towns of Fairdale and Rochelle.
Two people were killed, at least 20 others were sent to the hospital with injuries and others remain unaccounted.
Ashley is a professor in the meteorology program at Northern Illinois University.
Here is what he saw:
The two images (below) show the early formation of a tornado in Franklin Grove, Ill., about 10 miles to the west of Rochelle. At the time the photos were taken, the tornado was about one-minute old.
The photos (below) show the huge “wedge” tornado north of Rochelle, Ill., along Interstate 39, near State Road 64. Wedge tornadoes are relatively rare in Illinois.