CHICAGO (AP) — An unusually massive line of storms packing hail, lightning and tree-toppling winds today could affect more than one in five Americans as it rolls from Iowa to Maryland.
Meteorologists were even warning about the possibility of a weather event called a derecho, which is a storm of strong straight-line winds spanning at least 240 miles. The storms are also likely to generate tornadoes and cause power outages that will be followed by oppressive heat, said Russell Schneider, director of the National Weather Service's Storm Prediction Center in Norman, Okla.
"We're becoming increasingly concerned that a major severe weather event will unfold," Schneider said. "The main thing is for folks to monitor conditions and have a plan for what to do if threatening weather approaches."
For the first time this year, the center was using its highest alert level for parts of Iowa, Illinois, Indiana and Ohio. The storms will start in late afternoon in eastern Iowa, Schneider said, and could hit Chicago around rush hour.
All told, the area the weather service considers to be under heightened risk of dangerous weather includes 74.7 million people in 19 states.