SURVEYING DAMAGE

Brian Smith, a National Weather Service forecaster in North Little Rock, said damage assessment teams were surveying several counties on Friday after the reports of several tornadoes.

Several storms produced straight-line wind damage and heavy repeated rain, causing flash flooding across Arkansas, he said.

Little Rock received more than 3 inches (7.6 cm) of rain in an hour, breaking the hourly record for the state capital, with more thunderstorms and heavy rain possible on Friday, he said.

Large, long-lasting thunderstorms known as supercells are responsible for producing the strongest tornadoes, along with large hail and other dangerous winds.

Oklahoma City and Tulsa, as well as Springfield, Missouri, may all be buffeted by Friday's severe weather and possible tornado touchdowns, said Rich Thompson, a lead forecaster at the National Weather Service's Storm Prediction Center in Norman, Oklahoma.

The danger zone included Joplin, Missouri, he added. Joplin was hit by a monster tornado, one of the most catastrophic in US history, that killed 161 people and destroyed about 7,500 homes two years ago.

On Friday, the focus was going to be from southwest Missouri into Oklahoma, Thompson said, referring to the area often referred to as "Tornado Alley".

The twisters on Thursday sent Oklahoma residents scrambling for cover 10 days after a deadly EF-5 tornado struck Moore, Oklahoma, and killed 24 people. The May 20 tornado damaged or destroyed about 13,000 homes in the Oklahoma City suburb.