It's beginning to look a lot like White Christmas Eve as snow falls in ...

Some residents in the Northeast and Mid-Atlantic regions woke up to a White Christmas Eve on Tuesday morning.

Around 20 million people are under winter weather alerts across the regions, which received upwards of an inch of snow. Washington, D.C., and New York City may see an inch of snow, while parts of northern New England could see 2 to 6 inches of snow, especially in the mountains of Vermont, New Hampshire and Maine.

Metropolitan hubs that will be impacted by this storm system include Washington D.C., Philadelphia and Burlington, Vermont.

The National Weather Service is advising people who need to drive to do so slowly and safely as the snow may be slick.

Christmas Eve travel was briefly snarled as the Federal Aviation Administration issued a nationwide ground stop for all American Airlines flights on Tuesday. The airline said a “vendor technology issue” was the reason for the ground stop, and not the weather.

But can residents in the area expect a White Christmas? It seems unlikely. This snow is expected to last about two hours and move out quickly, with improving conditions by early Tuesday afternoon. As of Tuesday morning, the Christmas Day forecast for the Northeast is chilly but dry.

Frosty temperatures being seen in the Northeast are also expected to subside.

"Much of the East Coast region will have a moderation trend in the cold temperatures going into Christmas Eve, as the arctic surface high moves offshore and milder air from the Ohio Valley advects eastward across the region," the National Weather Service said.

In the West, a storm system bringing low elevation rain and mountain snow to the region continues.

Around 2 to 4 inches of rain is expected along the coast from the Pacific Northwest into central California, while the Sierra Nevada could see up to a foot of snow.

Residents are advised to stay away from the coast, where "dangerous and life-threatening beach conditions" with coastal flooding has been seen, according to the weather service's Bay Area field office.

The Santa Cruz Wharf collapsed Monday as a result of major storm swells, sending three people into the ocean and leaving them with minor injuries.

By Christmas Day, this storm will bring some snow to the Rocky Mountains as the next storm system moves into the West Coast from the Pacific.