A map provided by the National Weather Service showed that the storm began west of Newcastle and crossed the Canadian River into Oklahoma City's rural far southwestern side about 3 p.m. When it reached Moore, the twister cut a path through the center of town before lifting back into the sky at Lake Stanley Draper.
The National Weather Service issued an initial finding that the tornado was an EF-4 on the enhanced Fujita scale, the second most powerful type of twister.
The Storm Prediction Center in Norman, Okla., forecast more stormy weather on Tuesday, predicting golf ball-sized hail, powerful winds and isolated, strong tornadoes for parts of Texas, Arkansas, Louisiana and Oklahoma. The area at risk does not include Moore, Okla.
Monday's powerful tornado loosely followed the path of a killer twister that slammed the region with 300 mph winds in May 1999. It was the fourth tornado to hit Moore since 1998.
The weather service estimated that Monday's tornado was at least a half-mile wide.
Moore Mayor Glenn Lewis, who was also mayor during the 1999 storm, said the city was already at work on the recovery.
"We've already started printing the street signs. It took 61 days to clean up after the 1999 tornado. We had a lot of help then. We've got a lot of help now."
Monday's devastation in Oklahoma came almost exactly two years after an enormous twister ripped through the city of Joplin, Mo., killing 158 people and injuring hundreds more.
That May 22, 2011, tornado was the deadliest in the United States since modern tornado record keeping began in 1950, according to the National Oceanic and Atmospheric Administration. Before Joplin, the deadliest modern tornado was June 1953 in Flint, Mich., when 116 people died.
Associated Press writers Sean Murphy and Sue Ogrocki contributed to this report.
The Associated Press