Winter storm warnings were in place across much of the Great Lakes region on Wednesday, with hazardous travel conditions likely.

Forecasters said the snow that fell in the Mid-Atlantic Tuesday was dry and fluffy to the north of Washington, D.C., but heavier and wetter to the south. Why is this? Air temperature is the primary factor in determining the kind of snow that falls.

More than 90 million people were under winter weather alerts overnight, with the heaviest snow due for northern Kentucky into West Virginia.