The storm is barreling up the Atlantic Ocean and likely to converge with two other major weather systems — a winter storm in the west and a blast of cold air from Canada — as it moves ashore.

The combined effect could be devastating.

"Most experts agreed that if the worst-case scenarios play out, it could be the most severe storm to hit the East Coast in a generation," The New York Times' Marc Santora writes.

Here's what to expect if Sandy makes landfall.