PORTLAND — Northern New England residents prepared Sunday for high winds, heavy rains and widespread power outages from the massive storm approaching the region.

Hurricane Sandy was headed north from the Caribbean and was expected to come ashore late Monday or early Tuesday, most likely in New Jersey, colliding with a wintry storm moving in from the west and cold air streaming down from the Arctic. The resulting megastorm was expected to arrive in Maine, New Hampshire and Vermont with sustained winds of 30-40 mph and gusts of 50-60 mph and higher.

The region will get 1 to 3 inches of rain on Monday and Tuesday, with some localized areas getting 4 to 5 inches, said National Weather Service meteorologist Margaret Curtis in Gray.

Seas were expected to build to 15 to 25 feet off southern Maine and New Hampshire, and coastal erosion is expected, she said.

“The heaviest rain will be Monday and into early morning Tuesday. Tuesday we’ll still be seeing wind in the 20-30 mph range and fairly heavy rain,” she said.

Officials said there were concerns of downed trees and power lines, and the potential for flash flooding and coastal erosion. After the storm’s peak, the rain is expected to last for a couple more days, adding to the risk of localized flooding and high waters levels in streams and rivers.

Concerns are especially high in Vermont, where rains from last year’s Tropical Storm Irene caused the most devastating natural disaster in the state since flooding in 1927.

Irene, which rumbled through region 14 months ago, cut off about a dozen Vermont communities and left thousands of people displaced after raging rivers destroyed bridges and roads.

Green Mountain Power, the state’s largest utility, said it’s secured more than 250 additional line workers and tree trimmers to assist Green Mountain crews restore power to customers. Utility line crews from Canada were scheduled to arrive Sunday night, with others from as far away as Tennessee and Florida arriving in the overnight hours and into Monday.

Maine Gov. Paul LePage signed a limited emergency declaration Friday allowing power crews from other states and Canada to help with power restoration and waiving federal rules to extend the hours of service that repair crews can work.

In New Hampshire, Ann Romney, the wife of Republican presidential nominee Mitt Romney, cancelled speaking engagements in Derry and Manchester due to the storm. The Romney campaign said the campaign bus would be used for relief efforts throughout the East.