Marty Marr, a farmer in New Berlin, Illinois, holds up a corn stalk that had been flattened by the derecho that charged through the Midwest on Thursday, June 29, 2023. (Twitter/@ilcorn)

Sometimes called an "inland hurricane," a derecho is a rare, bowed line of thunderstorms, with hurricane-force wind gusts often over 100 mph. The storms cause massive wind damage over a large area, often leaving behind significant damage and power outages that can last for days to weeks.

The term “derecho” comes from the Spanish word for “straight,” a nod to the powerful, straight-line winds that cause the most destruction. In contrast, “tornado” comes from the Spanish word meaning “to turn,” highlighting the key difference in wind behavior.

A line of storms called a derecho powers across the mid-Atlantic on June 29, 2012.

One of the most famous derechos occurred on June 29, 2012, when a storm complex developed in northern Illinois and caused massive wind damage all the way through Washington, D.C. More than 4.2 million electric customers lost power during the event.

Most recently, a derecho caused damage from Illinois to Pennsylvania on June 8, 2025, and a strong derecho caused massive damage to corn fields in Iowa in 2023.

Historically, derechos were most commonly defined with a dimensions of 250 miles long and 60 miles wide. Earlier this year, NOAA's Storm Prediction Center (SPC) introduced 11 specific meteorological criteria to define a derecho.

The massive storms are most common in the Plains and Midwest and are usually generated from Mesoscale Convective Systems, which are often stronger in the overnight hours.

Due to the widespread, intense winds, people should prepare for an approaching derecho the same way they would if a tornado were approaching.

It’s important not to confuse derechos with squall lines — both are lines of thunderstorms, but they behave differently. A squall line typically forms along or just ahead of a cold front and marks the boundary between air masses. Some squall lines stretch more than 1,000 miles and can travel similar distances in extreme cases. However, while squall lines may weaken quickly or bring scattered severe weather, derechos tend to sustain their intensity and deliver widespread, long-track wind damage.

Steve Golias, of McDounagh, Ga., looks at the remains of a cable internet service tower that fell in front of his mother's house in Falls Church, Va., Saturday, June 30, 2012. (AP Photo/Cliff Owen)

"Derechos and their parent thunderstorm complexes often form and move along the northern edge of a large rim of heat," AccuWeather Senior Meteorologist Dan Pydynowski said. This region often aligns with a strong upper-level jet stream, which supercharges the storms and propels them forward at remarkable speeds. There are exceptions, however, like the one that hit the Northeast on April 29, 2025.