x

Science

AP Explains: What Is A Derecho?

December 21, 2021

Multiple tornadoes and thunderstorms that struck the Great Plains and upper Midwest on Dec 15 were the result of a rare event called a derecho, according to the National Weather Service’s Storm Prediction Center. It was the first on record in December in the United States.

WHAT IS A DERECHO?

A derecho is often described as an inland hurricane.

According to the National Weather Service, the term comes from the Spanish word “derechos” to mean “direct” or “straight ahead” and was first used in 1888 by a chemist and professor of physical sciences.

The storm has no eye and its powerful winds come across in a line. That can cause widespread overall damage and smaller pockets of severe damage.

Ryan Maue, a private meteorologist in the Atlanta area and a former chief scientist for the National Oceanic and Atmospheric Administration, said a derecho can develop from a series of separate storms, usually carrying hail and strong winds, that combine and build into a larger bowing complex.

The term “bow” describes how it appears on radar.

When that happens, the system “can subsist on its own, it will continually fuel itself,” Maue said. “It can cause tremendous damage with straight-line winds.”

HOW OFTEN DO THEY OCCUR?

Derechos are relatively rare events, and in the U.S. are more likely to occur in the Corn Belt, an area that ranges from Minnesota and Iowa south and eastward toward the Ohio Valley, according to the National Weather Service.

They’re more likely to occur from May through August, particularly during periods of high heat — making the December derecho so uncommon.

“The climatology of derechoes depends on the location and season, but if you consider the entire US (east of the Rockies), then you’ll usually see one or two, possible more per year depending upon the weather patterns,” Maue said.

WHAT DAMAGE CAN IT CAUSE?

A 2020 derecho that traveled from eastern Nebraska across Iowa and parts of Wisconsin and Illinois reached wind speed of a major hurricane. The National Weather Service’s Storm Prediction Center reported winds approaching 100 miles per hour (161 kilometers per hour) in multiple places. In Cedar Rapids, Iowa, residents emerged from their homes to find an estimated 100,000 trees had been snapped or torn out of the ground.

A 2009 storm dubbed a Super Derecho by the National Weather Service traveled from western Kansas to eastern Kentucky. It caused several deaths and injuries and more than $500 million in damages by the time it had traveled more than 1,000 miles (1,609 kilometers).

A 2003 derecho traveled from Arkansas through several southern states including Alabama, Georgia and South Carolina. Two people died and 11 were hurt.

Last week’s storm system spawned at least 45 tornadoes and caused widespread damage. Five deaths have been blamed on the storms.

ARE THERE DIFFERENT TYPES OF DERECHOES?

Yes. The August 2020 storm system was the result of what is known as a progressive derecho. The Dec. 15 event was a serial derecho.

The weather service said a progressive derecho is fueled by a hot and moist environment with relatively strong winds aloft. Serial derechos are produced by storms with strong winds that bow outward, the service said. They sweep across an area both long and wide, driven by the presence of very strong winds in the atmosphere.

The unprecedented December warm spell included temperatures that rose to 70 degrees Fahrenheit (21 degrees Celsius) as far north as Wisconsin, creating evening temperatures that weather historian Chris Burt compared to that of a “warm July evening.”

 

RELATED

Our modern and fast-paced diet often makes us overlook some crucial issues related to our health and well-being.

Top Stories

Columnists

A pregnant woman was driving in the HOV lane near Dallas.

General News

NEW YORK – Meropi Kyriacou, the new Principal of The Cathedral School in Manhattan, was honored as The National Herald’s Educator of the Year.

Video

2 Germans, a Spaniard and a Senegalese Killed in Building Collapse in Spain’s Mallorca Island

MADRID (AP) — Spain's National Police on Friday gave details on four people killed when a building housing a bar and restaurant club collapsed on the island of Mallorca.

THRU JUNE 4 NEW YORK – The third iteration of the Carte Blanche project featuring Maria Antelman with the work ‘The Seer (Deep)’ opened on April 19 and runs through June 4, Monday-Friday 9 AM-2:30 PM, at the Consulate General of Greece in New York, 69 East 79th Street in Manhattan.

ATHENS – An Archieratical Divine Liturgy and a memorial service honoring the 50th dark anniversary of the Turkish invasion of Cyprus at the Metropolis – the Greek Orthodox Cathedral of Athens – marked the beginning of the 4th Archon International Conference on Religious Freedom of the Archons of the Ecumenical Patriarchate on Sunday, May 26.

NEW YORK – Greek-American Republican congresswoman Nicole Malliotakis gave a strong and clear response to reports by American media such as The Hill and Politico regarding the purpose of her presence at the trial in the well-known ‘hush money’ case against former President Donald Trump.

NIKOSIA - Dust and other potentially toxic emissions are being caused by renovations at the Makarios Children’s Hospital in Nicosia which specializes in treating cancer cases, charities helping there have complained.

Enter your email address to subscribe

Provide your email address to subscribe. For e.g. [email protected]

You may unsubscribe at any time using the link in our newsletter.