Town battered by tornado braces for more twisters

Residents and rescue crews searching for survivors in the tornado-ravaged town of Joplin, Mo., are bracing for the possibility of more twisters as the death toll from Sunday's massive storm climbed to at least 122.

"It looks like prime time for the greatest tornado coverage and intensity will be between 3 to 4 p.m. and 9 to 10 p.m.," meteorologist David Imy told The Associated Press.

Heavy storms were forecast for Joplin from 6 p.m. to midnight, according to forecasts.

"That will be when the greatest coverage and most intense storms occur," Imy said.

According to the Oklahoma-based U.S. Storm Prediction Center, there is a moderate risk of severe weather in central and southeast Kansas, as well as southwestern Missouri on Tuesday.

Central parts of Oklahoma, southern Kansas and northern Texas are at "high risk," though, indicating that tornadoes will hit in those areas.

In their comments to reporters Tuesday, officials overseeing the rescue effort said that, because the safety of search crews remains a priority, they will be asked to stop should the weather take a turn for the worse again.

So far, the death toll stands at 122, with another nine people pulled from the rubble alive. Sunday's tornado is America's deadliest since a single twister touched down in Flint, Mich., in 1953.

It's the eighth deadliest single tornado in U.S. history.

Talking to reporters Tuesday, Joplin fire chief Mitch Randles said the first phase of a search covering every building and structure damaged by the twister is over, with the second sweep expected to be concluded by Tuesday

"It's really incredible the fact that we're still finding people," Randles said.

Regardless of the precise count now, the number of dead is expected to rise as crews are able to dig further into the piles of rubble that now stand where buildings once stood.

"Clearly, it's on its way up," Gov. Jay Nixon told The Associated Press, stopping short of suggesting how high it might go. But he has vowed that crews will keep working until everyone is accounted for.

"They still think there are folks that could be alive," Nixon added.

Just days after the twister cut its swath of destruction, the prospect of rebuilding seems a long way off.

For now, rescuers racing against the looming storms are also coping with dangerous conditions that include fires from gas leaks, downed power lines and the instability of many structures left standing when the tornado tore through on Sunday.

Thousands of homes were destroyed, hundreds of businesses levelled, and churches and schools reduced to rubble when the twister ripped through the city.

One of the town's hospitals, St. John's Regional Medical Center, also appeared to have sustained a direct hit, leaving five patients dead.

The twister was one of more than 50 reported across seven Midwestern states over the weekend, and the second deadly tornado disaster to strike the U.S. in less than a month.

Unlike the series of tornadoes that roared across six Southern states in April, Joplin was hit by just one powerful twister that U.S. National Weather Service Director Jack Hayes said rated the preliminary label of an EF4. That's the second-highest rating assigned to twisters based on the damage they cause.

According to Hayes, the tornado was, at times, more than a kilometre wide and packed winds blowing in excess of 300 kilometres per hour.

A former mining town, Joplin is located on the famous highway known as Route 66, about 225 kilometres south of Kansas City. Because of its location in the so-called "Tornado Alley," the town's population of approximately 50,000 people are accustomed to dealing with such weather events.

The heavy rain and hail that was falling at the time may have not only drowned out the sound of the warning sirens, however, they might also have obscured the scale of the storm.

In the midst of a three-day state visit to Britain, U.S. President Barack Obama promised to personally visit the stricken region on Sunday.

"The American people are by your side," Obama told reporters in London, explaining that he is pledging all available federal resources to rescue and recovery efforts in the Missouri town.

According to the U.S. National Weather Service, outbreaks of multiple tornadoes have claimed more lives, including the pack that left 314 dead in six southern states on April 27.

With files from The Associated Press