(CNN) A tornado warning has been issued for parts of Texas Friday as a powerful storm system with severe rain, tornadoes, ice, snow and flooding moves across the US.

The tornado warning is in effect for portions of Tarrant and Dallas counties in Texas as well as the Dallas/Fort Worth International Airport, Fort Worth and Arlington, according to CNN meteorologist Taylor Ward.

Millions of people in the eastern half of the United States -- in the Southeast, Midwest, Great Lakes Region and the Northeast -- could feel the effects of the storm system moving across the US, said CNN meteorologist Dave Hennen. Another storm system will bring heavy snow to the West.

Weather alerts have been issued for the following states in the eastern half of the US:

Nearly 50 million people are under a flood watch in parts of Texas, Oklahoma, Arkansas, Missouri, Kentucky, Illinois, Indiana, Ohio, New York and Vermont.

About 35 million are under a winter weather alert in parts of Oklahoma, Kansas, Nebraska, Iowa, Illinois, Wisconsin, Michigan, New York, New Hampshire, Vermont and Maine.

And more than 20 million are under a wind advisory in parts of Texas, Louisiana, Alabama, Mississippi, Florida, Kentucky and Indiana.