OMAHA, Neb. — Tornadoes were spotted across the Midwest and Plains Saturday as an outbreak of unusually strong weather seized the region, and forecasters sternly warned that "life-threatening" weather could intensify overnight.
Storms were reported in Kansas, Iowa, Nebraska and Oklahoma. Emergency officials in Iowa said that high winds or a tornado damaged a hospital in Creston, but no injuries were reported. Authorities also said about 75 percent of the small western Iowa community of Thurman was destroyed, with no injuries reported there either.
In Nebraska, baseball-sized hail shattered windows and ripped siding from houses. In Oklahoma, more than 5,000 people gathered for a rattlesnake hunt in Woods County scattered when a tornado touched down there, said the county's emergency management director, Steve Foster.
National Weather Service forecasters issued sobering outlooks that the worst of the weather would hit around nightfall, predicting that conditions were right for exceptionally strong tornadoes. Weather officials and emergency management officials worried most about what would happen if strong storms hit when people were sleeping, not paying attention to weather reports and unlikely to hear warning sirens. When it's dark, it's also more difficult for weather spotters to clearly see funnel clouds or tornadoes.
"This could go into, certainly, to overnight situations, which is always of immense concern to us," said Michelann Ooten, an official with the Oklahoma Department of Emergency Management.
The Storm Prediction Center in Norman, Okla., which specializes in tornado forecasting, said that the outbreak could be a "high-end, life-threatening event" nearly two days before the weather hit.
It was just the second time in U.S. history that the center issued a high-risk warning more than 24 hours in advance. The first was in April 2006, when nearly 100 tornadoes tore across the southeastern U.S., killing a dozen people and damaging more than 1,000 homes in Tennessee.
While there were no fatalities as of Saturday evening, storm spottings were plentiful. Storms were erupting faster than storm spotters could tally them all. The danger kicked off Saturday morning when tornado sirens sounded in Oklahoma City around dawn.
One of the suspected tornadoes in central Oklahoma hit near the small town of Piedmont, and followed a similar path as a tornado last May that killed several people, Mayor Valerie Thomerson said. Later in the day, several tornadoes were reported to have touched down in the northeast part of the state. But besides damage to a camper, the chaos was minor.
In Iowa, Thurman, a town of about 250 people, was severely damaged by a possible tornado. Fremont County Emergency Management Director Mike Crecelius said that about 75 percent of the town was destroyed, but there were no injuries or deaths. Crecelius said the town was on lockdown Saturday night and wasn't letting anyone in. He said town officials and residents expect to start cleaning up on Sunday.
In Creston, about 75 miles from Des Moines, the Greater Regional Medical Center suffered roof damage and had some of its windows blown out by a storm, said John Benson, a spokesman for Iowa Homeland Security and Emergency Management. Patients were being moved to a hospital in Osceola, about 30 miles away. No injuries were reported.
Strong storms knocked out power in Des Moines, Council Bluffs and Sioux City. The National Weather Service in Des Moines also received reports of high winds that toppled at least five semis on Interstate 29.
In southeast Nebraska, an apparent tornado took down barns, large trees, and some small rural structures.
In northeast Nebraska, Boone County Sheriff David Spiegel said baseball-sized hail had damaged vehicles, shattered windows and tore siding from houses in and around Petersburg, about 140 miles northwest of Omaha. Johnson County emergency director Clint Strayhorn said he was still trying to determine how long the twister was on the ground and how much damage it did.
"I'm on a 2-mile stretch that this thing is on the ground and I haven't even gotten to the end of it yet," he said Saturday afternoon as he walked the path of destruction near the Johnson-Nemaha county line. He didn't immediately know of any injuries.
Two possible tornadoes were reported father south in Nebraska near the Kansas border, and as many as 10 others were reported in largely rural parts of western and central Kansas, including one north of Dodge City that was said to be on the ground for a half-hour, weather officials said.
In Salina, Kan., tornado sirens sounded after a possible tornado was spotted nearby. National Weather Service meteorologist Mike Scott also said tornadoes were reported in the central and western Kansas counties of Pratt, Stafford, Rush and Hodgeman. There were reports of a home damaged in Rush County and an old schoolhouse damaged in Hodgeman County.
Tornado threats caused some weekend festivities to be called off. The threat prompted University of Nebraska-Lincoln athletic officials to cancel the annual spring football game minutes before Saturday's kick-off.
The McConnell Air Force Base in Wichita, Kan., relocated 16 aerial refueling tankers to Grand Forks Air Force Base in North Dakota because of the risk of hail from the storms. And four air refueling aircraft from Forbes Field in Topeka were flown to Kirtland Air Force Base in New Mexico, and three other aircraft were moved into hangars to protect them from the potential for large hail in the Shawnee County area.
Forecasters warned that even once the danger Saturday night passed, the threat from the storm system wasn't over. Severe weather was also possible for a significant band of the center of the country on Sunday.
"The threat isn't over with tonight, unfortunately. Severe weather is possible again tomorrow from east Texas and Arkansas and up into the Great Lakes," said Bill Bunting, chief of operations at the Storm Prediction Center, which is part of the National Weather Service.
Associated Press reporters David Pitt in Des Moines, Iowa; Sean Murphy and Rochelle Hines in Oklahoma City; Heather Hollingsworth in Kansas City, Mo.; Erin Gartner in Chicago; and Ed Donahue in Washington contributed to this report.