A powerful storm system that tore across the United States in recent days is poised to move offshore into the Atlantic Monday, but in its wake are devastated communities across multiple states that were hit with violent tornadoes,

The dynamic storm from Friday through Sunday had earned an unusual “high risk” designation from weather forecasters.

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.

The deadly storm system arrived on the East Coast on Sunday after thunderstorms and tornadoes swept through the South and Midwest.

As many as 150 million people in the U.S. face a potential severe weather outbreak in the coming days. Storms will likely reach the Tampa Bay area late Sunday, bringing a marginal risk of severe weather to part of the region.