Blizzard warnings and travel advisories were up on Martha’s Vineyard Friday as a powerful northeast winter storm made its way up the mid-Atlantic.

The Steamship Authority announced that all ferry service would be suspended Saturday.

The National Weather Service has posted blizzard warnings for most of eastern, northeastern and southeastern Massachusetts, effective from 7 a.m. Saturday to 5 a.m. Sunday. Heavy and possibly historic snow accumulations of 18 to 24 inches are in the forecast, with hurricane-force winds in coastal areas including the Cape and Islands, the weather service said.

On the Vineyard preparations were under way for the storm, with emergency managers, including fire chiefs, highway officials and others meeting Islandwide.

The Steamship Authority announced ferry cancellations  for at least all day Saturday. The utility giant Eversource said extra crews were being sent to the Island to prepare for expected power outages. The Vineyard Transit Authority has canceled all bus service on Saturday.

Coast Guard sector southeastern New England in Woods Hole issued a bulletin Friday advising mariners to remain in port and secure their vessels.

Preparations were under way at Coast Guard station Menemsha as well.

“We’re basically just making sure that everything around here is battened down,” petty officer Ryan Martyn told the Gazette by phone Friday.

Island towns and the county began issuing announcements about downtown parking bans, closures and overnight warming shelters in the event they are needed.

Information is being posted on town and county websites.

Harbor Homes, located at Martha’s Vineyard Community Services (first building on the left), announced it will extend hours, opening from Friday at 6 p.m. until Sunday at 10 a.m., with three meals a day, and capacity for 18 guests. Contact Lisa Belcastro at 508-560-3678.

The Martha’s Vineyard Agricultural Society announced that its barns are available for temporary emergency animal housing. Contact Lauren Lynch at 732-687-3412, Brian Athearn at 508-962-2477, or Garrison Vieira at 508-989-0039 for more information.

Call the Animal Shelter of Martha’s Vineyard at 508-627-8662 for emergency needs for small pets.