Dozens of warnings are being issued in rapid-fire succession Saturday afternoon in Mississippi and soon Alabama. Several storms are producing what appear to be large, long-lived tornadoes. Forecasters at the National Weather Service are pleading with residents to stay aware of the weather and heed the warnings today;

At least 12 fatalities have been reported in Missouri, according to the Missouri State Emergency Management Agency. The deaths come as a massive storm system moving across the country unleashed winds that damaged buildings, whipped up deadly dust storms and fanned more than 100 wildfires.

Millions of Americans across the country are on alert for a severe weather outbreak as violent, long-track tornadoes with damaging winds of up to 80 mph and large hail are expected across the Midwest and South with the cross-country storm moving east.