The National Weather Service confirms at least one tornado has touched down in a Tulsa suburb.
Meteorologist Pete Snyder says the tornado touched down in Broken Arrow about 8:40 p.m. Thursday and caused "considerable" damage.
Snyder said he had not heard of any injuries or fatalities.
A woman who answered the phone at the Broken Arrow Police Department also confirmed a tornado and said the department had "no response at this time."
Earlier in the day, tornadoes touched down in Oklahoma and Arkansas, injuring at least nine people.
The National Weather Service had reported two tornadoes on the ground near Perkins and Ripley in north central Oklahoma and another west of Oden, Ark.
All nine of the injured were in Arkansas; two of the injuries were attributed to a lightning strike in Rogers. Lightning was also believed to have started a fire that destroyed two floors of a condominium building in northwestern Indiana.
Some trees, homes and power lines were damaged in Arkansas. Emergency Management spokesman Tommy Jackson said first responders had trouble reaching a destroyed home where one person was hurt because a number of trees were blocking the road.
In Oklahoma, Perkins Emergency Management Director Travis Majors said there were no injuries or damage there. Ripley, about 10 miles east of Perkins, did not seem to have significant damage. The Payne County emergency management director did not immediately return a phone call seeking comment.
Storms also caused problems in the western Iowa town of Onawa, damaging buildings, breaking windows, tearing awnings and blowing down trees and a stoplight. National Weather Service meteorologist Dave Fobert told the Sioux City Journal that the damage apparently was caused by a thunderstorm, not a tornado.
Thursday's tornadoes were much less dangerous than the EF5 storm that struck Moore, Okla., on May 20 and killed 24 along its 17-mile path. The U.S. averages more than 1,200 tornadoes a year, but top-of-the-scale storms like the one in Moore — with winds over 200 mph — happen only about once per year. The tornado last week was the nation's first EF5 since 2011.
CBS News meteorologist David Bernard reported Thursday morning the Great Plains area already saw 75 tornadoes since Sunday.
Some strong winds blew through Moore, in suburban Oklahoma City, on Thursday, but the weather didn't cause significant problems for crews cleaning up from last week's tornado.
This spring's tornado season got a late start, with unusually cool weather keeping funnel clouds at bay until mid-May. The season usually starts in March and then ramps up for the next couple of months.
The Storm Prediction Center in Norman, Okla., warned that there was a moderate risk of severe weather Thursday over much of eastern and central Oklahoma, with storms also possible in the rest of the central United States from Texas to Wisconsin. Flooding is also a concern in parts of Missouri, Iowa and Illinois through Sunday.
In addition to tornadoes, the storms were bringing rain and hail.
"Right now we've been getting a few thunderstorms, but they're very severe supercell thunderstorms," said Michael Scotten, a meteorologist with the National Weather Services. "The whole storm rotates, and they produce on occasion some tornadoes and heavy hail."
The severe weather threat led organizers to postpone the start of the outdoor Wakarusa Music Festival near Ozark, Ark., which will feature Widespread Panic, The Black Crowes and the rapper Snoop Lion (formerly known as Snoop Dogg). An estimated 15,000 sought shelter from lightning and wind Thursday, according to the Times Record newspaper of Fort Smith, Ark.
Of the 60 EF5 tornadoes since 1950, Oklahoma and Alabama have been struck the most, seven times each. More than half of these top-of-the-scale twisters have occurred in just five states: Alabama, Iowa, Kansas, Oklahoma and Texas.