ARLINGTON, Va. − A wall of snow, ice and rain was sweeping across the Northeast on Thursday, the first in a series of storms forecast to wallop much of the nation's northern tier over the next several days.

A winter storm that brought snow, sleet and freezing rain to a large swath of the Midwest swept into the mid-Atlantic and Northeast on Thursday, causing treacherous travel conditions, prompting school delays and closures and potential power outages for millions of Americans.

Forecasters are warning of possibly significant ice accumulations in several mid-Atlantic states that could cause widespread power outages and disrupt travel.