Businesses in New York and New Jersey that were preparing insurance claims for losses from Superstorm Sandy now have a second headache: how to deal with new losses from an early winter snow storm. The snow and wind from the nor’easter made continuing power outages worse, once again snarled road and rail traffic, and may have contributed to fresh damage at businesses that had not made repairs yet from Sandy. Disaster modeling companies expect Sandy caused as much as $20 billion in insured losses, not counting flood damage that could add billions more to the total.