Feb 23 (Reuters) - A winter storm across parts of the U.S. Northeast has left more than 511,000 homes and businesses without power, and officials across the region have warned of heavy snow, strong winds and dangerous travel conditions.

The hardest-hit utilities included Eversource Energy ES.N in Massachusetts, where 135,797 of its 3.3 million customers were without power, followed by FirstEnergy, with more than 81,257 of its 6.2 million U.S. customers affected, according to PowerOutage.us.

The total number of power outages in New Jersey stands at 129,761.

The storm has made travel along the East Coast difficult. Airlines cancelled thousands of flights and officials urged people to stay off the roads.

Here are the major outages by state:

(Reporting by Anjana Anil in Bengaluru; editing by Barbara Lewis)

((Anjana.Anil@thomsonreuters.com;))