CHICAGO—A tornado that swept through Chicago’s western suburbs, damaging more than 100 homes and injuring several people, was packing 140 mph winds when it hit the heavily populated area, the National Weather Service said. A weather service team that surveyed the aftermath of Sunday night’s storm found that, based on Monday’s preliminary findings, the tornado was an EF3 on the Enhanced Fujita scale when it cut a path through parts of Naperville, Woodridge, Darien and Burr Ridge, and that it launched debris to a height of nearly 20,000 feet. The weather service planned to continue surveying that area to determine the precise path, width and length of the storm’s trail of destruction, said Jake Petr, a meteorologist at the service’s Romeoville office. “So overall, we’re still solidifying the findings for the whole event of this tornado,” he said Tuesday. Woodridge Mayor Gina Cunningham said Tuesday that the tornado dealt significant …