EF3 tornado in St. Charles County, Missouri

The tornado developed about a third of a mile northeast of the intersection of Highway 94 and Osage Ridge Road in southwestern St. Charles County around 7:32 PM CDT. As it moved to the northeast, two houses sustained minor damage and one outbuilding was destroyed on Highway T, just north of intersection with Hemsath Road. The tornado continued northeast and strengthened as it approached Highway F, northwest of Defiance. Multiple homesteads and farms suffered varying degrees of property damage along Highway F to Highway 94. Two homes were completely destroyed. The first home was 110 years old and did not appear to have any anchoring to the concrete foundation. The second home just 100 yards east of the first was swept clean to the subfloor, which was still anchored to the concrete foundation. One fatality and two injuries occurred at this location. The damage was rated EF3 with winds to 165 mph. The tornado continued northeast, crossing the Missouri River and Howell Island before entering St. Louis County in Chesterfield Valley. Dollar amount damage is estimated around $3.4 million.

Numerous severe thunderstorms formed ahead of an approaching cold front during the late afternoon and evening of Friday December 10th, 2021. Large hail, damaging winds and five tornadoes occurred across central and eastern Missouri as well as south central Illinois. Unfortunately two of the tornadoes were very strong (rated EF-3 on the Enhanced Fujita Scale) and responsible for 7 fatalities (one near Defiance, Missouri and six at an Amazon Facility near Edwardsville, Illinois). The Defiance, MO tornado tracked within one mile of the NWS St. Louis office in the Missouri Research Park near Weldon Spring, MO leading to the staff sheltering while NWS Kansas City provided service backup. This is only the third time in the office's existence that the staff had to shelter. The damage from the Defiance, MO EF3 tornado was estimated at $684,186 and is unknown for the remaining tracks at this time but early estimates are well into the millions due to the damage sustained at the Amazon facility near Edwardsville, IL.