Oklahoma Gas and Electric Co. and firefighters worked to the clear downed power lines and free trapped motorists.
Robert Ruiz, of Norman, said he and his family had about three minutes between the time they heard the announcement to seek shelter and the time storm hit downtown.
Ruiz, a partner with Enye Media at 301 1/2 E Main St., said the storm ripped off his back door and threw it about 25 feet after he, his wife and four children rushed to take cover there.
As they hunkered down in the middle of a recording studio in the business, they saw heavy rain and debris flying past the window.
“It was raining hard, and then all of a sudden, everything went sideways,” Ruiz said. “All the rain went sideways, and we starting seeing debris. There was a roar, and the kids got really scared of the situation. They had their heads down and their hands on the back of their heads, and they started crying.”
The chaos lasted about a minute, he said.
OG&E reported 4,000 customers without power in Norman, 1,500 in Oklahoma City and 1,500 in Piedmont about 6 p.m. Friday.
Norman city officials canceled household hazardous waste collection scheduled for Saturday, though a spring cleanup will continue as planned.
Elsewhere Friday evening in Oklahoma, there were preliminary reports of a tornado north of Altus near the Blair community in Jackson County, one near Cooperton in the eastern Kiowa County and another tornado south of Carnegie in western Caddo County. Those reports had not been confirmed as of 9 p.m. Friday, the weather service said.
Emergency responders throughout Oklahoma began to organize this week in anticipation of the Saturday storms, state Emergency Management Department spokeswoman Keli Cain said. The agency plans to open its emergency operations center by 3 p.m.
Authorities are coordinating with local emergency management officials, meteorologists, law enforcement officers, paramedics, firefighters and others in preparation for the storms, Cain said.
Similar advance planning was under way Friday in cities across the state. Officials in nearly every department in Oklahoma City were meeting to go over plans and procedures, city spokeswoman Kristy Yager said.
Officials' priorities are ensuring every method of informing the public about weather conditions is used effectively, and to coordinate a fast response to help people in areas affected by any tornadoes and other severe weather.
How to stay safe
Authorities strongly recommend people seek shelter in their own homes. A safe room, basement or other underground shelter is ideal. Otherwise, sheltering on the lowest possible floor inside an interior room with no windows, like a closet or bathroom, is best.
Those who plan to go to a relative, friend, neighbor or workplace that has an underground shelter should head there well before the weather is expected to hit. Driving during a severe storm, or soon before one is expected to hit, could be dangerous.
Officials recommend having a radio that's not dependent on electric power available in case electricity service is cut off. Surrounding people in the sheltered area with blankets, pillows, padding or other protective gear is also recommended.
Authorities urge residents to keep their cellphones fully charged, prepare a kit with emergency supplies and keep their identification and car keys with them at all times.