Id UPDATE: DERECHOS

The opening item of the Q&A of the September 2020 issue was about a type of intense storm called a derecho, which is at least 50 miles wide and features straight-line winds with gusts of at least 58 miles per hour. Such storms usually cause wind damage across a distance of at least 240 miles. On August 10, 2020, a huge derecho made headlines as it blasted the Midwest, sweeping across an 800-mile swath of the country for a duration of 14 hours and leaving 1 million people without power. The storm passed through Nebraska, Iowa, Wisconsin, Indiana, and Illinois. Iowa was the hardesthit state, reporting 10 million acres of damaged crops (about one-third of the state’s yield) as well as devastation of the power grid and damage to structures, including big grain bins being flattened that resulted in destruction of tens of millions of bushels of grain. In Cedar Rapids, Iowa’s second most populous city, winds in excess of 110 miles per hour caused damage that was described as widespread and significant. Recovery from the fierce derecho took weeks in some areas.