What is a ‘derecho’ and how much damage could one inflict on NYC?

Posted at 6:33 PM, Jun 13, 2013
and last updated 2013-06-13 18:59:49-04

Severe thunderstorms whipped through the Midwest bringing flooding rains and roaring winds.

From Illinois to the east coast the storms tore down trees and power lines and had experts worrying a derecho would form when the storms combined.

But what exactly is a derecho?

I went to Liberty Science Center to ask some of the experts.

Harold Clark, who runs the STEM Educators and Programs, helped us figure it out.

“A derecho is a particular kind of severe windstorm,” Clark said.

Clark says the derecho is characterized by a series of thunderstorms spread out over a big distance.

“They’re caused by downdrafts, air rapidly dropping and then moving forward so all the wind is in the same direction.  You don’t have that cyclic motion.”

The name derecho was actually coined by a meteorologist back in the 1880’s.

Since the word tornado has a Spanish origin, he chose the name derecho, which translates to straight — an obvious choice, considering thunderstorms appear to line up during one of these storms.

The damage these storms can do in rural areas is bad enough.  But in a city filled with skyscrapers, it could be devastating.

With most storms the higher you go, the stronger the windgusts will be, which would make this I-beam walk extremely difficult out in the real world.  But with a derecho, the strongest windgusts are on the ground level and they can reach more than 100 miles per hour, which means most of the destruction can be seen right on the street.

“If you have these severe winds over a 240 mile width and you go for several hundred miles you can have a huge geography that can be affected with downed trees and downed powerlines.”

And in the canyon like streets of New York, that could cause a massive damage.

Fortunately, these storms never reached the criteria to cause damage of derecho proportions.

But for many, even a little rain that comes with the storms can cause big headaches.

“In my neighborhood the ground is just very wet and the water has no place to go,” Enrico Paola said.

So derecho or no derecho, people are still afraid of flooding every time it rains.