The most fatalities as of Saturday morning were in Missouri, authorities said, with an estimated 11 people killed.

A sweeping storm system moving across the U.S. threatens to bring tornadoes, blizzards and possibly wildfires to different regions of the country

Eleven storm-related fatalities were reported in the Missouri counties of Ozark, Butler, Wayne and Jefferson, the state highway patrol said. Three people were confirmed dead in Independence County, Arkansas, the state's emergency management division said. Four were reported dead in Texas, officials said Saturday.

About 47 million people faced an enhanced to moderate severe storm threat from Madison, Wisconsin, to Birmingham, Alabama.

Most of the rest of north Alabama will have a Level 2 risk, and a small area in the northeast corner of the state will have a Level 1 risk. If storms can develop they have the potential to be intense, especially west of Interstate 65. Tornadoes, damaging winds and hail will be possible.