SENECA, Mo. - Another round of storms moved Tuesday into tornado-ravaged areas of Missouri, Arkansas and several other states where residents are still picking up from the weekend's killer twisters.

The National Weather Service said conditions could be similar to those that spun funnel clouds and killed 27 people Saturday and Sunday in the Plains and the Southeast.

A tornado warning was issued for southern Shelby County in northeast Missouri on Tuesday after one was spotted there. There were no immediate reports of injuries or damage.

Even if the latest storms aren't particularly violent, they'll make for a soggy cleanup in towns such as Picher, Okla., where Tressie Gilmore and four family members emerged from a pile of debris that used to be their house Saturday evening, shaken but with nothing worse than bruised ribs.

On Monday, the 25-year-old joined family and friends in salvaging what they could from what remained of her mother and stepfather's home after the tornado - packing wind estimated at 165 to 175 mph - slammed into Picher, killing seven.

"It felt like evil," she said. "It didn't feel like Mother Nature. It felt personal."

Eight of the 23 victims in Oklahoma and Missouri died in cars, troubling experts who say the inside of a vehicle is one of the worst places to be during a twister.

"It's like taking a handful of Matchbox cars and rolling them across the kitchen floor," Sgt. Dan Bracker of the Missouri State Highway Patrol said, surveying the damage in and around Seneca, near the Oklahoma line. "This is devastating."

Two people were killed in Georgia, where meteorologists said at least six tornadoes touched down. Another man was killed in northern Alabama when his truck was struck by a falling tree limb as he was surveying storm damage.

A southern Illinois woman was killed Sunday when wind toppled a tree onto her car, according to the Randolph County Sheriff's Office.

Authorities say drivers and their passengers should find a sturdy shelter or even lie flat in a ditch or other low spot, covering their heads with arms, coats or blankets if a tornado is moving in their direction. Overpasses and bridges should also be avoided - overpasses can create a wind-tunnel effect, and bridges can collapse.

Officials from the Federal Emergency Management Agency, which determines whether residents qualify for federal assistance, were in Missouri and Oklahoma. FEMA Director David Paulison and Homeland Security Secretary Michael Chertoff were scheduled to visit the hardest hit areas Tuesday.

Scientists from the Environmental Protection Agency arrived in Oklahoma on Monday to check for high lead levels in Picher, a heavily polluted former mining town where lead-filled waste is piled into giant mounds.

Miles Tolbert, Oklahoma's secretary of the environment, said he did not believe there was any immediate hazard to the 800 residents. But he said more testing was needed.

The weather service said about 100 people have died in U.S. twisters this year. This could become one of the deadliest tornado years in recent history.

The weather service's Storm Prediction Center in Norman, Okla., said 130 people died in U.S. tornadoes in 1998, the eighth deadliest year since 1950. The highest number of tornado-related deaths came in 1953, when 519 people died.

To date this year, 910 tornadoes have been reported, though not all have been confirmed by the weather service. That compares with 1,093 confirmed twisters for all of last year.

Harold Brooks of the National Severe Storms Laboratory said the highest number of tornadoes ever recorded through May 11 of any year was 676 in 1999. Brooks said he expects the number of confirmed tornadoes through mid-May of this year to end up in the 650-to-700 range.

Tornado season typically peaks in the spring and early summer, then again in the late fall.