Severe weather is expected to bring subzero temperatures the northern Plains as soon as Thursday, then reach the Mississippi Valley, the Northeast and the Ohio Valley by Sunday.

A massive winter storm is barreling toward the eastern U.S., threatening to bring severe ice and snow from Texas to Boston.

According to The Weather Company forecasters, Fern could affect over 230 million in the U.S. with snow and/or ice, two-thirds of the nation's estimated population.