OKLAHOMA CITY — In an unusually early and strong warning, national weather forecasters cautioned Friday that conditions are ripe for violent tornadoes to rip through the nation from Texas to Minnesota this weekend.
Storms were already kicking off in Norman, Okla., where a twister whizzed by the nation's tornado forecasting headquarters but caused little damage.
It was only the second time in U.S. history that the Storm Prediction Center issued a high-risk warning more than 24 hours in advance, said Russ Schneider, director of the center, which is part of the National Weather Service. The first time was in April 2006, when nearly 100 tornadoes tore across the southeastern United States, killing a dozen people and damaging more than 1,000 homes in Tennessee.
This weekend's outbreak could be a "high-end, life-threatening event," the center said.
It's possible to issue earlier warnings because improvements in storm modeling and technology are letting forecasters better predict storms and with greater confidence, said Chris Vaccaro, a spokesman for the National Weather Service.
The worst weather is expected to develop late this afternoon between Oklahoma City and Salina, Kan., but other areas also could see severe storms with baseball-sized hail and winds of up to 70 mph, forecasters said. The warning issued Friday covers parts of Illinois, Iowa, Kansas, Missouri, Nebraska, Oklahoma and Texas.
Storms were developing as cold air from the west hit low-level moisture coming up from the Gulf of Mexico, said Scott Curl, another weather service meteorologist.