The National Weather Service is officially classifying last week’s wind event which roared through the Midwest a derecho.

According to the agency,  a serial derecho moving at 60-70 mph tracked from Kansas to Wisconsin, resulting in over 400 reports of damaging wind and several tornadoes.

A derecho is a widespread, long-lived wind storm sometimes also called an “inland hurricane”.

Although a derecho can produce destruction similar to the strength of tornadoes, the damage typically is directed in one direction along a relatively straight swath. As a result, the term “straight-line wind damage” sometimes is used to describe derecho damage. By definition, if the wind damage swath extends more than 240 miles and includes wind gusts of at least 58 mph or greater along most of its length, then the event may be classified as a derecho.

The record-breaking, and historic, wind event caused widespread damage across much of the Great Plains, including Kansas. The event also led to numerous grassfires, severe weather, damaging wind gusts, and blowing dust.

This is the first derecho ever recorded in the U.S. in the month of December.