The storm was reclassified as a "powerful post-tropical cyclone" over the North Atlantic just before 11 a.m. EDT on Tuesday, according to the National Hurricane Center.
Over the weekend, Ernesto initially had weakened to a tropical storm late Saturday after bringing heavy rain and strong winds to Bermuda, but no injuries were reported, Bermuda Security Minister Michael Weeks said Sunday afternoon.
The storm then picked up strength as a hurricane again early Monday, as it headed farther out in the Atlantic toward easternmost Canada
The National Hurricane Center's 11 p.m. Monday report shows winds of 80 miles per hour with higher gusts.
Forecasters think it will accelerate in the open Atlantic.
Swells generated by Ernesto were affecting portions of Bermuda, the U.S. East Coast, as well as the Canadian Atlantic coast. Life-threatening surf and rip current conditions are likely in these areas during the next couple of days, the hurricane center said.
The weather service posted a coastal flood advisory and warned of a high risk for rip currents along the Atlantic coast through Monday evening, saying they "can sweep even the best swimmers away from shore into deeper water."
A warning extended from Florida to the Boston area and portions of Maine.
RELATED: Hurricane Ernesto triggers another house collapse along North Carolina Outer Banks
Forecasters, citing local emergency management, said a 41-year-old man drowned Saturday in a rip current at Surf City, North Carolina.
And two men drowned off South Carolina's Hilton Head Island on Friday where rip current warnings were posted. They were identified as Ralph Jamieson, 66, of South Euclid, Ohio, and Leonard Schenz, 73, of Loveland, Ohio. It could be weeks before autopsy results can determine whether the deaths were related to Ernesto, Beaufort County Coroner David Ott said.
Rough seas from Hurricane Ernesto have sent at least one home into the ocean in Rodanthe, North Carolina.
VIDEO: Sea swallows beach home in North Carolina
Video and pictures posted by Chicamacomico Banks Fire & Rescue show the breathtaking scene with debris littering the beach and a whole home floating in the surf.
CNN contributed to this report.