National Weather Service forecasters say they are growing increasingly confident that New England will see either a close pass or a direct hit from Hurricane Sandy early next week.
“One thing we know for sure is we are going to feel some impact from it. We don’t know if it will be an all-out hurricane impact or if it will make landfall to our south over the mid-Atlantic. One thing we have ruled out is it moving out to sea,’’ said Glenn Field, warning coordination meteorologist at the weather service office in Taunton.
The storm is expected to move up the East Coast, then turn west and make landfall.
“Where it decides to hook left is what’s going to determine everything for everybody,’’ Field said. “Anyone from Maryland to Maine is under the gun. But somebody is going to get whacked.’’
The storm will be powerful and widespread, he warned, and “if it gets up in our area, all bets are off.’’
Even if the storm makes landfall to the south, it will likely roil the ocean, stirring up mighty waves of 40 to 50 feet in the open ocean and 25 feet along the coast, Field said.
The weather service today issued a hazardous weather outlook and a marine weather statement that warned of a “dangerous and potentially life-threatening storm’’ for mariners. The service advised mariners to return to port by Saturday and continue to monitor weather forecasts.
Supercomputer forecasting models show that the Category 2 hurricane could make landfall on the East Coast anywhere from Maryland to Maine late Monday into Tuesday.
At 2 p.m., the storm packed maximum sustained winds of 105 miles per hour as it moved through the Bahamas. It was moving north at 20 miles per hour, according to the weather service’s National Hurricane Center
Sandy will likely fluctuate between a Category 1 and Category 2 storm as it makes its way toward New England, said weather service meteorologist Charlie Foley.
It will transform in the mid-Atlantic and lose some of its tropical characteristics, he said.
A tropical hurricane typically has a compact core, but Sandy’s core will expand as it hits colder water. Wind speeds might not be as high once the storm affects New England, but they will affect a wider area, he said.
“The makeup of the storm itself will change once it hits that colder air … and the jetstream,’’ he said.
An area of high pressure in the Atlantic will likely prevent the storm from shifting out to sea, Foley said.
“Normally, a storm like this would head north and work its way over the colder waters and lose its energy and dissipate,’’ he said.
But in Sandy’s case, the models are forecasting a shift to the west, toward the land.
Whether the storm makes landfall in New England or passes close by, Foley said property damage is possible.
Sandy could cause snowfall in areas of higher elevation, butBoston will only see rain, Foley said.
Trees still have their leaves, which makes them more susceptible to being blown down and falling on power lines. Foley said power outages similar to those caused by last year’s Hurricane Irene are possible with Sandy.
“Those people suffered for a long time because they didn’t get their power back for a while,’’ he said. “That, of course, is in the back of people’s minds.’’
Foley said the track and strength of the storm will change over the next few days, but forecasters are confident the storm will get close to New England shores or hit them directly.
“There is no certainty. If you take the worst-case scenario, you want to be prepared for that,’’ he said. “This is a major event. This is something that people want to take seriously.’’
The Massachusetts Emergency Management Agency offered tips to minimize the potential impact of the storm.
“Early planning and preparation can be the key to your safety,’’ MEMA director Kurt Schwartz said in a statement. “It is important to use your time wisely and not wait until the last minute to ensure your family’s safety.’’
The agency encouraged people to have a well-stocked disaster kit to use during a power outage.
People should trim trees, clear rain gutters, secure outdoor furniture, and to make temporary plywood covers for windows and sliding doors, the agency said.
Boat owners should remove their vessels from the water this weekend, MEMA said.
People are also encouraged to download MEMA’s ping4alerts! mobile app for weather alerts.
NStar is monitoring the storm and has taken steps to ensure a more effective response to power outages than during last year’s big storms.
“We’re all on high alert here,’’ said NStar spokeswoman Caroline Pretyman. “We’re closely monitoring the forecast. The exact path of the hurricane is uncertain.’’
NStar officials have conducted planning meetings in preparation for Hurricane Sandy, she said.
“We’re reaching out to outside crews and contractors for any extra help we might need,’’ Pretyman said.
NStar officials also met with community leaders about how to better share information during an emergency, she said.
“If a hurricane hits, there will be power outages, and so it’s our job to respond as quickly and as safely as possible,’’ Pretyman said.
The utility provider launched an online outage map accessible by smartphone and on NStar’s website. The map allows users to report outages and track the company’s progress in restoring power.
“Last fall’s historic snowstorm caused unprecedented damage across the region and interrupted power to more than 200,000 NStar customers,’’ Werner Schweiger, president of NStar, said in a statement. “We’re now better positioned to more quickly address emergencies, coordinate the restoration process with our communities and communicate with our customers.’’
National Grid is also keeping an eye on the storm, said spokeswoman Charlotte McCormack.
Officials are ramping up their internal communications and have contacted the contractors that National Grid usually works with, putting them on alert, McCormack said.
“They’ll be here before the weekend so they’ll be in place before the storm gets here, if that’s the path it takes,’’ she said.
Both companies were criticized for their response to power outages from last year’s Hurricane Irene and Halloween snowstorm.