Forecasters are predicting a significant chance of strong tornadoes this weekend across a large part of the nation's mid-section, an outbreak that could stretch from the Great Plains to the Midwest and South.
It's been a quiet year for tornadoes so far, but that doesn't mean the placid weather won't take an abrupt turn, forecasters said Thursday.
"Our run of relatively quiet weather may be about to come to an end," Bill Bunting, operations chief for the Storm Prediction Center in Norman, Okla., said.
Bunting said the coming system will start Saturday in the Plains — Nebraska, Kansas, Oklahoma, Texas and a sliver of South Dakota — and move eastward into Missouri, Arkansas and Louisiana on Sunday. The system is expected to stretch into parts of Illinois, Kentucky, Tennessee, Mississippi and Alabama later Sunday.
Strong winds in the upper and middle atmosphere will meet most air moving north from the Gulf of Mexico, creating conditions conducive for tornado development, Bunting said.
"The threat is there and folks need to monitor the latest information from the National Weather Service," Bunting said.
Bunting said that people in the affected areas should be aware that dangerous weather is possible. But when it comes to exactly where and how dangerous, he said it's too early to say.
Large hail and damaging straight-line winds of more than 70 mph are likely, in addition to possible tornadoes. The system is expected to bring heavy rain, so flash flooding and even some river flooding is possible, according to the National Weather Service.
The Midwest and South haven't seen many severe storms yet this spring, but Bunting noted that residents in the forecast area are accustomed to violent weather this time of year.
Bunting said people who are headed to outdoor activities, from golf outings to spring festivals, should make sure they can receive weather warnings in case they need to quickly find shelter.
The Oklahoma City Memorial Marathon is scheduled for Sunday and organizers are emphasizing their alert system to notify participants and spectators of approaching storms. The marathon has three parking garages near the start and finish lines where people can take shelter. A color-coded warning system will be in place at medical aid stations that dot the course.
If people need a reminder of how dangerous tornadoes can be, this weekend marks the third anniversary of a 175-twister, multi-day outbreak that killed 316 people, the third-deadliest outbreak in U.S. history.
The fatalities occurred as 122 tornadoes swept through on April 27, 2011, striking parts of Mississippi, Alabama, Tennessee, Virginia and Georgia.