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.

The National Weather Service issued an ice storm warning​ for parts of the area and winter weather advisories for other areas in western Pennsylvania.

Storm Freya and Garnett, two more storms are in the forecast through late next week, some of which will hit similar parts of the Northeast, Midwest and Plains. Here's what you need to know.