A winter storm is likely to make travel difficult or dangerous along the East Coast Tuesday and Wednesday as millions of people visit family and friends on Thanksgiving. The National Weather Service has predicted heavy rain and wind in New England, the mid-Atlantic, and the Carolinas, which could turn to snow and sleet inland and at higher elevations.

The service issued winter storm warnings for upstate New York, western Pennsylvania and parts of Ohio, predicting that travel will be dangerous or impossible in those areas.

A winter weather advisory is in effect for other areas from northeast Tennessee to Maine. A spokesman for the weather service told the Associated Press that conditions would affect travel by car and plane, potentially causing delays at busy airports in major cities.

The system began in the south and west, where heavy snow fell over the weekend. As the storm moved across the southern Great Plains, several people were killed on the roads because of the weather.

More snow is expected Tuesday and Wednesday in inland cities, including Pittsburgh, Syracuse, Rochester and Montreal, according to the weather service and media reports.

The storm is expected to have mostly passed by Thanksgiving, but the holiday will be windy, according to forecasters.

As of Tuesday morning, the weather service was predicting gusts of up to 38 miles per hour Thursday in New York. The large balloons in the Macy’s Thanksgiving Day Parade will be grounded if sustained winds are above 23 miles per hour with gusts above 34 miles per hour, according to a spokesman for the parade.