On Tuesday traffic was heavy mid-day on the Mass Pike West Bound in the Natick area. Even though Thanksgiving is two days away, people are already hitting the roads. Justin Hammet just drove through snow in Pittsburgh “I had to get new tires just to come out here.

The National Weather Service forecasts a rainy Tuesday and a rain-heavy Thanksgiving Day for Boston, with potential travel delays.

Winter weather could snarl travel plans for the millions of Americans traveling for the Thanksgiving holiday this year.