Updated Jan. 3, 2018, at 3:30 pm
The National Weather Service has issued a winter storm warning for Southeastern Massachusetts, including Martha’s Vineyard, beginning in the predawn hours of Thursday through the night. A coastal flood warning has also been issued.
The storm is being forecast to undergo bombogenesis, a slang term for when a powerful low pressure system develops rapidly. Warm eastern air from the ocean contrasting with cold western air from land creates the conditions for a powerful coastal storm. Over these two polarizing air temperatures is a jet stream which causes air to rise and starts the bombogenesis, according to the weather service.
Preliminary estimates were for three to four inches of snow, but that number has been increased to four to seven inches of snow for the Island, and as much as a foot or more of snow on the mainland. The farther the storm moves east, the colder the temperatures will be and the more snow will accumulate.
There is potential for high tides with coastal flooding and ice shifts. The National Weather Service issued an urgent marine weather message for mariners early Tuesday morning, warning of heavy freezing spray that can be “extremely hazardous to navigation.”
Tisbury harbormaster John Crocker reported that Vineyard Haven Harbor is free of sea ice, but that Lake Tashmoo is frozen solid and unnavigable.
USCG Auxiliary Flotilla 11-9 Commander Glen DeBlase said Menemsha Harbor is largely free of sea ice, though some ice has formed behind the Galley restaurant. The pond, however, is iced up and unlikely to be navigable, he said.
“There is heavy freezing spray expected. Thursday could gust 50 mph winds in Vineyard Sound. Could see seas four to seven feet,” Master Chief Robert Reimer of the U.S. Coast Guard said. The Menemsha Station usually uses weather like this for training, but the heavy freezing spray is a major concern. Chief Reimer expects rough waters, but is not concerned about the station’s readiness.
“Fully operational, ready to go,” he said. “If we’re needed, we’ll be ready to go.”
Winds with gusts of up to 50 mph are also expected, something that could interrupt ferry service and cause power outages.
Eversource has contractor line and tree crews on the Island, spokesman Michael Durand wrote in an email. The utility was preparing on Wednesday to send more in advance of the storm, he wrote.
Late Tuesday, the Steamship Authority issued an alert urging customers to watch its website for potential cancellations. To make or modify a reservation, call 508-477-8600, go online at steamshipauthority.com, or visit one of the terminals.
Martha’s Vineyard Airport is in storm preparation mode, according to Assistant Airport Manager Geoff Freeman. Plows and other vehicles are being fueled, and emergency generators tested. Should the storm bring powdery snow, that will be better for aircraft, he said. Should it dump “wet cement,” only an inch or two may be enough to shutter the airport, because aircraft manage poorly in that type of heavy, wet snow. Cape Air is currently flying on its regular winter schedule, he said, but he expected an update Wednesday night about changes to Thursday’s schedule.
The brunt of the storm will hit on Thursday, and is expected to taper off by Friday morning. Icy-cold temperatures will return through the weekend.
Reporter Rich Saltzberg contributed to this report.