The National Weather Service has determined the tornadoes that struck Sherman, Riverton and other county locations Friday packed winds of 130 miles per hour. Field crews are continuing their damage surveys and preliminary estimates are subject to change.
According to the NWS:
The Sherman tornado developed at 6:12 p.m. one mile northwest of Sherman in an open field, then caused damage to two houses and two outbuildings before crossing I-55. More significant damage was noted in a subdivision immediately east of I-55. There, numerous houses had severe roof and siding damage, and several outbuildings and detached garages were severely damaged. The tornado continued northeast into more rural areas, damaging two large barns at a horse farm. Minor damage was noted farther northeast, with sheet metal from outbuildings strewn into open fields.
The tornado traveled 5.5 miles and lasted for eight minutes. It's maximum width was 400 yards.
Riverton:
The tornado developed at 6:18 p.m. near the intersection of Overpass Road and Old Route 36, causing damage to trees. Northeast of this location, the roof was completely removed from a business. The remainder of the tornado path through northern Sangamon and southern Logan counties was mainly in open fields, with minor damage noted to farm outbuildings. The tornado dissipated near Latham, producing shingle damage to several houses in town.
The tornado traveled 21.1 miles and lasted for eight minutes. Its maximum width was 200 yards.
A tornado at Morrisonville is believed to have been an EF-0 with peak winds of 80 miles per hour. Beginning at 7:06 p.m., it lasted for two minutes and was on the ground for 4.1 miles, with a maximum width of 20 yards.
Minor damage was surveyed in rural areas to the west and north of Morrisonville. Several grain bins were destroyed and carried across an open field. Damage that occurred to 30 power poles east of Morrisonville was determined to be the result of intense straight-line winds.
