MINEOLA, N.Y. — Thanksgiving travelers scrambled to change their plans and beat a storm expected to bring snow, slush and rain to the crowded Washington-to-Boston corridor Wednesday on one of the busiest, most stressful days of the year.

Forecasters said major Northeast cities will probably see moderate to heavy rain most of the day, though New York and other places were also gearing up for several inches of snow.

Higher elevations west of the Interstate 95 corridor could see as much as 6 to 12 inches before the nor’easter exits Wednesday night, meteorologist Andrew Orrison said.

“I always go on Tuesday to try to avoid the Wednesday rush, but it seems like more people are leaving on Tuesday now,” said Bill Fraser, a landscaper from Henniker, New Hampshire, who was taking a train from Boston to New Rochelle, New York, to visit his mother for Thanksgiving.

Jenna Bouffard, a New York City public relations executive headed in the opposite direction, changed her bus ticket from Wednesday to Tuesday.