OMAHA, Neb. — Tornadoes were spotted across the Midwest and Plains on 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.
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, storms were erupting faster than spotters could tally them all. The danger began Saturday morning when tornado sirens sounded in Oklahoma City around dawn.