A rare storm packing 160km/h winds and with power similar to an inland hurricane has swept across the US midwest, blowing over trees, flipping vehicles, causing widespread property damage and leaving hundreds of thousands without power as it turned toward Chicago.
The storm known as a derecho lasted several hours on Monday as it tore across eastern Nebraska, Iowa and parts of Wisconsin, had the wind speed of a major hurricane, and likely caused more widespread damage than a normal tornado, says Patrick Marsh, science support chief at the National Weather Service's Storm Prediction Center in Norman, Oklahoma.
It's not quite a hurricane. It has no eye and its winds come across in a line, Marsh says, but the damage it is likely to do spread over such a large area is more like an inland hurricane than a quick more powerful tornado.
What makes a derecho worse than a tornado is how long it can hover one place and how large an area the high winds hit, Marsh says.
"Right now, it's making a beeline for Chicago," Marsh said mid-afternoon on Monday. "Whether or not it will hold its intensity as it reaches Chicago remains to be seen."
But the environmental conditions between the storm and Chicago are the type that would not likely diminish the storm, Marsh said. It would likely dissipate over central or eastern Indiana, he said.
Australian Associated Press