ComEd in Chicago yesterday deployed extra crews to respond to a powerful storm that swept through its service territory overnight and knocked out power for about 144,000 customers.

Approximately 138,000 customers have been restored since the storm struck. ComEd's goal is to restore service for the remaining customers by midnight Wednesday. A few isolated, complex outages may linger into Thursday morning.

The company has 600 crews in the field and has maintained additional staffing in its customer call center.

The storm pelted ComEd's service territory with approximately 46,000 lightning strokes, including 25,000 in its western region, 14,000 in the south, and 5,000 in the north and 1,000 in Chicago (see illustration above). Intense lightning can create surges of electricity that can damage transformers and utility poles and bring down power lines

"This summer's devastating storms have resulted from the weather pattern known as the 'Ring of Fire,' a term used by meteorologists to describe the high temperatures – or 'heat dome' – centered over the Midwest, compressing hot, moist air and destabilized by cold fronts," said Mark Rhein, a meteorologist at Murray and Trettel, Inc. "The jet stream over North Dakota and South Dakota has driven storm activity into northern Illinois, focusing storm damage repeatedly in ComEd's northern and western regions.

"The Ring of Fire currently over Illinois and neighboring states is the strongest of its kind in more than a decade," Rhein added.

More than 2.4 million ComEd customers have been affected by severe storms since June 1, and the summer is not yet over, setting a new record for the company. Approximately 1.4 million customers were affected by storms in the summer of 2007, and 1.2 million in both 2010 and 2008, all other prior years' storms affected less than 1 million customers.

Is 2.4 million service disruptions the new norm for weather in the Midwest?

"I wouldn't jump to that conclusion," said Eli Jacks, a meteorologist with the National Weather Service in Silver Spring, Md. "We are seeing record highs in many places in the country and seeing record highs for the low temperatures of the day, too, with 80s and 90s at night. But it's premature to say we should expect this every year.

"When you are at 20 below and buried in lake-effect snow, you'll forget all about this," Jacks said.