The remnants of Hurricane Isaac not only produced several inches of rain in central Illinois, but resulted in 9 short lived tornadoes - two during the evening of Friday August 31st and seven during the early afternoon of September 1st.
AUGUST 31, 2012
Two tornadoes rapidly developed in a rain band moving to the north-northwest through Morgan County early Friday evening. The first tornado touched down in an open field about 0.6 mile south of Franklin and produced structural damage to a house, mobile home, and auto repair shop around 5:12 pm Friday. The tornado injured a person and was rated as an EF1 - with wind speeds estimated around 90 mph. The tornado was short lived and dissipated after being on the ground for one-quarter mile and about one minute. A second tornado, from a separate storm, briefly touched down in a cornfield 3 miles west-northwest of Franklin around 5:32 pm, and dissipated in less than a minute. (See the map below)
September 1, 2012
Just before Noon until 1:30 pm, seven tornadoes were reported in central Illinois, about 25 miles north to northeast of Peoria. The center of the remnants of Isaac were centered in northeast Missouri, so the bands of rain - and the tornadoes that formed in them - were rotating toward the north and northwest.
The first two tornadoes briefly touched down near the town of Benson in Woodford County around Noon. No damage was reported with these weak tornadoes.
The third tornado formed 4 miles north-northwest of Benson at 12:05 pm, doing minor damage to the tin roof of a farm building. This tornado tracked for about 1.5 miles to the northwest - crossing the Woodford / Marshall County line, before dissipating about one mile east-southeast of Pattonsburg. This tornado was rated as an EF-0 with estimated wind speeds around 60 mph.
The fourth tornado formed at 12:32 pm on the Illinois River, about 1.5 miles southeast of Hopewell. This weak tornado dissipated rapidly and did no damage.
The fifth tornado developed at 1:08 pm about 4.5 miles east-southeast of Wyoming. The tornado was on the ground for about 1.2 miles before dissipating at 1:11 pm. No damage was reported with this weak tornado.
The sixth tornado formed near the Stark / Marshall County line, about 4 miles southeast of Castleton shortly after 1:10 pm. This tornado tracked for about 3 minutes to the northwest, dissipating about 3 miles southeast of Castleton around 1:14 pm. No damage was reported with this weak tornado.
The seventh and final tornado developed at 1:24 pm about 4 miles north of Wyoming in an open field. This tornado was on the ground for less than one mile and dissipated in about two minutes. No damage occurred with this weak tornado.