A cross-country storm, a blast of Arctic air and an outbreak of showers and thunderstorms are threatening to snarl traffic and pile up delays at airports over Thanksgiving holiday weekend, one of the nation's busiest travel periods.

Thursday will be a First Alert Weather Day as steady rain, wind and cooler temperatures arrive. Places north and west of New York City may also see some snow . Holiday travelers will catch a break Wednesday, but unfortunately they will have to navigate some wet weather on Thanksgiving.

A powerful winter storm packing heavy snow, rain and even severe weather is threatening Thanksgiving travel plans for millions as people across the U.S. leave home ahead of the holiday to celebrate with friends and family.