Follow as a winter storm is expected to bring heavy snowfall, icy roads and cold temperatures from the southern states to the Northeast.

What will happen?: The forecast could change, and change again, before the weekend. While forecasters are fairly confident that a storm will develop, key details — including its strength, where it will go and how much snow or ice it will deliver — remained uncertain on Tuesday.

Three Texas siblings who perished in an icy pond were among several dozen deaths in U.S. states gripped by frigid cold Tuesday as crews scrambled to repair hundreds of thousands of power outages in the shivering South and forecasters warned the winter weather is expected to get worse.