More than a dozen possible tornadoes have been reported in the United States as forecasters warned residents across the nation’s midsection to brace for life-threatening weather. 
Tornadoes hit Nebraska, Kansas and Oklahoma, and strong storms pushed through Iowa on Saturday, where officials said about 75 percent of the town of Thurman was destroyed in a twister, although no deaths or severe injuries were immediately reported. 

But the most dangerous weather was expected to come Sunday, and the US National Weather Service issued a warning for residents from East Texas to the Great Lakes to prepare. The weather service’s Storm Prediction Center said there was a possibility for a "high-end, life-threatening event." It was just the second time in United States history that the center had issued a high-risk warning more than 24 hours in advance. 
The first was in April 2006, when nearly 100 tornadoes tore across the Southeast, killing a dozen people and damaging more than 1,000 homes in Tennessee alone. On Saturday, officials in Thurman locked down the town after the tornado struck, said Mike Crecelius, the director of emergency management in Fremont County, Iowa. 
Crecelius said some residents took refuge in City Hall, which was the only building in town that still had power. In southeast Nebraska, barns were destroyed and trees uprooted in what appeared to be a tornado on Saturday afternoon.
In Boone County, in northeast Nebraska, the sheriff, David Spiegel, said baseball-sized hail damaged vehicles, shattered windows and tore siding from houses in and around Petersburg, about 140 miles north of Omaha. 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 half an hour, officials said. 
In central Oklahoma, what was believed to be a tornado hit near the small town of Piedmont, following the path of a tornado that killed several people last May, Mayor Valerie Thomerson said. Strong storms in Iowa knocked out power in Des Moines, Council Bluffs and Sioux City, and high winds knocked over at least five tractor-trailers on Interstate 29.
Source: BNA