Hurricane Ernesto was heading toward Bermuda on Thursday, after its winds knocked out power to hundreds of thousands of people and dumped torrential rain on Puerto Rico.

The storm, which strengthened into a hurricane after passing by Puerto Rico on Wednesday, was last passing over open water about 605 miles south, southwest of Bermuda at a rate of about 13 mph. Its maximum sustained winds were blowing at 85 mph, according to the National Hurricane Centers 8 a.m. advisory.

“Satellite imagery indicates that Ernesto is gradually strengthening,” the NHC said in a 2 a.m. ET update.

The National Hurricane Center and Bermuda Weather Service issued a hurricane warning early Thursday for Bermuda, meaning sustained winds of 64 knots, or about 74 mph, are expected in the island’s marine area within 36 hours.

A vehicle damaged after Ernesto hit Fajardo, Puerto Rico, on Wednesday.Jaydee Lee Serrano / AFP – Getty Images

HC Director Dr. Michael Brennan said in a video briefing Wednesday that when the center of Ernesto passes near or over Bermuda on Saturday, the hurricane is likely to be “at or near major hurricane intensity.”

The National Hurricane Center advisory said Ernesto is forecast to strengthen over the next day or two, and could become a major hurricane by Friday.

Bermuda Minister of National Security Michael Weeks has urged people to take the storm seriously and to prepare for its impact.

“As I have said before, it only takes one storm to cause significant damage and disrupt our way of life,” Weeks said Wednesday. “Now is not the time for complacency.”

Meanwhile, tropical storm warnings for Puerto Rico, its outlying islands of Vieques and Culebra, and the U.S. and British Virgin Islands were discontinued after the storm passed through the region.

“I know it was a long night listening to that wind howl,” U.S. Virgin Islands Gov. Albert Bryan Jr. said at a news conference.

No deaths related to the storm have been reported in Puerto Rico, but there were over 730,000 customers were left without electricity Wednesday, with some also losing water service, Gov. Pedro Pierluisi said.

A little more than 10 inches of rain fell in the region of Barranquitas in Puerto Rico, the National Weather Service in San Juan said, and much of the island was still under flood watches as of late Wednesday.

Dramatic video posted to social media showed the moment sailors were rescued from a stranded tugboat off the island of Sint Maarten as it was blasted by high winds and heavy rain Tuesday.

Police block a flooded road in Fajardo, Puerto Rico, as Ernesto passed through the area on Wednesday.Jaydee Lee Serrano / AFP – Getty Images

In advance of Ernesto hitting Puerto Rico, President Joe Biden issued an order authorizing the Department of Homeland Security and the Federal Emergency Management Agency (FEMA) to coordinate disaster relief efforts and supplement local disaster relief.

Swells from Ernesto are already affecting portions of the Caribbean islands and swells are expected to reach the east coast of the U.S. Thursday night and continue into the weekend — likely to cause life-threatening surf and rip current conditions, the NHC said.

Canadas Hurricane Centre said that while it was too soon to be certain, the current path of Ernesto puts it on course to affect the eastern provinces of Newfoundland and Nova Scotia at the end of the week.

Ernesto is the fifth named storm and third hurricane of what has already been an exceptionally busy hurricane season.