A Midwestern storm that may become the region’s second-most severe on record knocked out power to thousands in Illinois, Indiana and Michigan and forced the cancellation of hundreds of flights at Chicago airports.
The cyclonic system, whipping thunderstorms off its tail, was moving northeast into Canada while lashing states in the eastern and central U.S. with wind, rain and tornadoes.
The storm’s central pressure, an indication of its strength, was one of the lowest recorded in the Northern Hemisphere at about 8:30 a.m. Chicago time, said Travis Hartman, energy weather manager and meteorologist for MDA Federal Inc.’s EarthSat Energy Weather in Rockville, Maryland.
“It’s actually pretty impressive; we’re seeing wind, hail, rain, tornados, pretty much the sky is the limit,” Hartman said. “Everywhere from Chicago to the Appalachian Mountains looks to see some sort of severe weather.”
The pressure is equivalent to a Category 2 hurricane, and the system has upper-atmosphere wind speeds of more than 100 mph (161 kph), said Jeff Masters, co-founder of Weather Underground in Ann Arbor, Michigan. The storm is expected to last through tomorrow, the National Weather Service said.
“It is not a just a six-hour wind event, it is a prolonged wind event for a couple of days,” said Tom Kines, a senior expert meteorologist at AccuWeather Inc. in State College, Pennsylvania.
The tail of the storm will make its way to New York overnight, losing much of its punch by the time it reaches the East Coast, said Lauren Nash, a weather service meteorologist in Upton. Winds will be about 10 mph to 15 mph, she said.
Chicago O’Hare airport traffic resumed after departures were halted for about an hour earlier today, said Paul Takemoto, a spokesman for the U.S. Federal Aviation Administration. Winds at the airport gusted as high as 46 mph.
More than 450 flights were canceled at O’Hare as of 1:30 p.m. local time, according to the Chicago Department of Aviation. Delays were running 45 minutes or longer at O’Hare, while Chicago Midway delays were about 30 minutes.
O’Hare is the second-busiest U.S. airport and is a hub for United Continental Holdings Inc. and AMR Corp.’s American Airlines. Midway’s largest carrier is Southwest Airlines Co.
The U.S. Coast Guard closed parts of the Mississippi River in Iowa and Illinois to maritime traffic.
As many as 85,000 Commonwealth Edison customers in the Chicago area were without power as of 7:30 a.m. local time, according to a statement on the company’s website. Chicago, Joliet and Aurora were the hardest hit.
In northern Indiana and southern Michigan, 13,539 customers were without power as of 1:30 p.m. Eastern time, according to Indiana Michigan Power, a unit of American Electric Power.
The storm was forecast to be the second-most severe on record for the Midwest, surpassing the Nov. 10, 1975, storm that sank the freighter Edmund Fitzgerald in Lake Superior, an event immortalized by singer Gordon Lightfoot, according to the weather service.
The Edmund Fitzgerald storm had a central pressure of 28.95 inches. The strongest storm recorded in the Great Lakes region was the “Great Ohio Blizzard” of January 1978, which had a central pressure of 28.05 inches.
Tornado watches extend from western New York through Pennsylvania, Ohio, West Virginia, Virginia, Kentucky, Tennessee, North Carolina, Georgia, Alabama and Mississippi. A watch was also in effect for southern Ontario, according to Environment Canada.
At one point, 11 simultaneous tornado warnings were issued along the squall line at the tail of the system, Masters said. A tornado warning means that radar has picked up rotation in the clouds or someone has reported seeing an actual funnel.
“This is a once in every five-to-10-years event we have going on here,” Masters said.
The storm also triggered a blizzard warning in North Dakota and parts of Montana, according to the weather service. As much as 9 inches of snow may fall near the Canadian and U.S. border.
The center of the system is currently near St. Cloud, Minnesota, and expected to move northeast toward Hudson Bay in Canada, Kines said.
The lowest pressure reading measured so far for the storm was about 28.35 inches, Kines said.
When a barometer reads about 30 inches it usually means good weather. “When you start talking about pressure below 29 inches, it is very unusual and it represents a very strong storm,” Kines said. “Pressure-wise, it is stronger than some hurricanes.”
When Hurricane Earl reached Category 3 strength in the Atlantic at the end of August, its central pressure was recorded at 28.20 inches.
Great Lakes cyclones aren’t like hurricanes, said Andrew Krein, a National Weather Service meteorologist in Romeoville, Illinois. The storms gather their energy from the jet stream and the upper atmosphere, while hurricanes draw their power from warm ocean waters and have the strongest winds wound tightly around the core.