LITTLE ROCK, Ark. — Snow and ice are forecast for the northeast of the country as a deadly storm that started on the West Coast last week gathers steam Tuesday and powers toward the East in time for Thanksgiving.

The National Weather Service warned that the storm would almost certainly upset holiday travel plans for those hoping to visit loved ones in the mid-Atlantic and northeast.

“The timing of the storm couldn’t be worse,” said Chris Vaccaro, spokesman for the weather service headquarters in Silver Spring, Md. “We are seeing numerous threats as the storm is beginning to develop and intensify.”

Vaccaro said heavy rain and high winds would impact travel by air and road in the northeast and mid-Atlantic, and that the weather in that part of the country could have a ripple effect on airports with departing and originating flights elsewhere.