EF2 tornado in Shelby County, Illinois

This tornado crossed from Fayette County in the National Weather Service St. Louis County Warning Area (CWA) into southern Shelby County in the National Weather Service Lincoln County Warning Area (CWA) at 9:26 PM CST. It downed several large wood power poles about 2 miles west of Herrick. The most significant damage occurred to a residence 1 mile north of Herrick where an addition to a house saw significant damage, causing injury to one person. The tornado continued northeastward, damaging several outbuildings and downing trees and power lines. The tornado lifted 2 miles northwest of Cowden at about 9:36 PM CST.

A deepening area of low pressure tracked from near Kansas City during the afternoon of December 10th to southern Lake Michigan by the pre-dawn hours of December 11th. An unseasonably warm and moist airmass surged northward ahead of the system, resulting in high temperatures reaching the lower to middle 60s across central Illinois. As the low and an associated vigorous short-wave trough interacted with the moderately unstable and highly sheared environment, several clusters of strong to severe thunderstorms developed during the late afternoon and evening of the 10th. Numerous rotating cells were observed, with a total of 6 tornadoes touching down across central Illinois. 5 of the tornadoes were rated EF-2, including one that injured a person just north of Herrick in Shelby County.