National Weather Service meteorologists surveyed the damage in Southern Marengo County and determined it was the result of an EF-1 tornado.
A tornado touched down south of Sweet Water along County Road 6. It continued northeastward and reached its maximum intensity along County Road 7. The tornado dissipated as it crossed Highway 10 just southeast of Sweet Water. Damage was limited to numerous snapped trees. This was the first of two tornadoes in the Sweet Water area that afternoon. The tornado damage path was 2.77 miles long and was 500 yards wide at its widest point. The maximum winds were estimated around 90 mph.