Wicked Weekend? Plains States Warned of Tornado Outbreaks Image credit: Michelle Lepianka Carter/The Tuscaloosa News/AP Photo The central and southern Plains states are bracing this weekend for a storm system that could bring tornadoes similar to the ones that devastated the South around this time last year. The National Oceanic and Atmospheric Administration's Storm Prediction Center issued a rare, high risk today for severe weather Saturday from Oklahoma through Kansas. Paul Walker, an Accuweather senior meteorologist, told ABC News today that a warning two days in advance of a storm was unusual and that the weekend "should be particularly dangerous." The center last issued a high-risk alert in April 2011, when 173 tornadoes touched down in one day during a storm system that hit seven states. The twisters left 345 dead and nearly $11 billion in damage. The National Weather Service even characterized one tornado that struck a Mississippi town as an EF-5, reserved for only the fiercest tornadoes. Walker said today that there could be numerous tornado sightings from Saturday afternoon to Saturday night. He said the twisters were expected to be on the ground for "quite a while" and that they should be of the moderate to strong variety in terms of strength. A strong storm system causing thunderstorms today in Southern California was moving toward the Rockies, Walker said, and energizing a warm, moist flow of air from the Gulf of Mexico. Those conditions, plus differing wind directions in the atmosphere and on the surface, will increase the likelihood of tornado-spawning storms, Walker said. "All the pieces of the pie are coming together to make a particularly dangerous situation," he said.