History of Derecho in Timeline

A derecho is a widespread and long-lived straight-line windstorm. It's associated with a fast-moving group of severe thunderstorms called a mesoscale convective system. Derechos are defined by their straight-line winds, distinguishing them from tornadoes which have rotating winds.

May 1998: Upper Middle West-Canada-New York State derecho

In May 1998, a derecho occurred in the upper Middle West, Canada, and New York State. It was one of the most common instances of severe weather outbreaks that may become less favorable to tornado production as they become more violent.

September 1998: Late-summer derecho strikes New York State area

In September 1998, a late-summer derecho struck upper parts of the New York State area after midnight, highlighting that late-year derechos are not always confined to Texas and the Deep South.

July 2002: Serial derecho in Germany

On July 10, 2002, a serial derecho in Germany killed eight people and injured 39 near Berlin, demonstrating that derechos can occur outside of North America.

July 2003: Midwestern U.S. derecho

On July 21, 2003, a derecho occurred across the Midwestern U.S., developing from an area of convection in eastern Iowa and maturing into a wavy squall line across western Ohio and southern Indiana. The system re-intensified and formed a large hook.

2003: Significant tornado and severe weather outbreaks

In 2003, significant tornado and severe weather outbreaks occurred, which were examples of situations during which the rare Particularly Dangerous Situation severe thunderstorm variety of severe weather watches were issued from the Storm Prediction Center of the U.S. National Oceanic & Atmospheric Administration.

2004: Significant tornado and severe weather outbreaks

In 2004, significant tornado and severe weather outbreaks occurred, which were examples of situations during which the rare Particularly Dangerous Situation severe thunderstorm variety of severe weather watches were issued from the Storm Prediction Center of the U.S. National Oceanic & Atmospheric Administration.

May 2009: Southern Midwest derecho

In May 2009, a derecho occurred in the Southern Midwest, further exemplifying the hurricane-like radar signatures that some derechos develop, including a central eye and surrounding bands of convection.

August 2010: Derecho strikes Estonia

On August 8, 2010, a derecho struck Estonia and tore off the tower of Väike-Maarja Church, further demonstrating the global occurrence of derechos.

July 2011: Derecho strikes Chicago, Illinois

On July 11, 2011, a derecho struck Chicago, Illinois, leaving more than 860,000 people without electricity, showcasing the impact of derechos on urban infrastructure.

June 2012: North American derecho causes widespread power outages

In June 2012, a North American derecho took out electrical power to more than 3.7 million customers, starting in the Midwestern United States, across the central Appalachians, into the Mid-Atlantic States during a heat wave.

August 2020: Midwest Derecho causes extensive damage

In August 2020, the Midwest Derecho delivered winds up to 63 m/s in the Cedar Rapids, Iowa area, damaging or destroying ten million acres of crops, and leaving over a million homes without basic services. The derecho caused over $7.5 billion in damages.

January 11, 2022: NOAA and Environment and Climate Change Canada revise derecho criteria

On January 11, 2022, the National Oceanic and Atmospheric Administration and Environment and Climate Change Canada formally revised the criteria for a storm to be classified as a derecho. A wind storm must meet the revised criteria.

May 2022: Derecho in southern Ontario and western Quebec

In May 2022, a derecho in southern Ontario and western Quebec caused 10 deaths and $875 million in property damage, reaching peak wind speeds of 190 km/h. The derecho was the sixth largest "insured loss event" in Canadian history.