The National Weather Service has confirmed that a powerful spring storm system spawned 12 tornadoes in six states in recent days.

Forecasters confirmed three tornadoes in Missouri, including two in the St. Louis area; three each in Arkansas and Alabama; and one each in Louisiana, Mississippi and Georgia.

Emergency officials said three people were killed in the storms, which unleashed tornadoes and winds strong enough to peel the roofs from homes in the Deep South and heaped snow and ice on the Midwest, leaving thousands without power.

The weather service is predicting that another storm system will bring wintry weather to the north-central U.S. starting Saturday afternoon, potentially bringing 6 to 12 inches of snow to parts of eastern Montana, much of North Dakota, northern South Dakota and northern Minnesota.