SAN JUAN, Puerto Rico (AP) — Hurricane Ernesto charged toward Bermuda on Friday as officials on the tiny island in the middle of the Atlantic Ocean prepared to open shelters and close government offices.

The Category 2 storm was located 320 miles (510 kilometers) south-southwest of Bermuda. It had maximum sustained winds of 100 mph (160 kph) and was moving north-northeast at 13 mph (20 kph).

Ernesto was expected to strengthen further on Friday before it passes near or over Bermuda on Saturday. Tropical storm conditions including strong winds and life-threatening floods were expected to start affecting Bermuda on Friday afternoon, according to the National Hurricane Center.

"Preparations to protect life and property should be rushed to completion," the center said.

The storm was forecast to dump between 6 and 12 inches of rain, with up to 15 inches in isolated areas. Forecasters noted that Ernesto was a large hurricane, with hurricane-force winds extending up to 70 miles (110 kilometers) from the center and tropical-storm-force winds extending up to 265 miles (425 kilometers).

In preparation for the storm, officials in the wealthy British territory announced they would suspend public transportation and close the airport by Friday night.

National Security Minister Michael Weeks had urged people to complete their hurricane preparations by Thursday.

"Time is running out," he said.

Bermuda is an archipelago of 181 very tiny islands whose land mass makes up roughly half the size of Miami, so it's uncommon for the eye of a hurricane to make landfall, according to AccuWeather.

It noted that since 1850, only 11 of 130 tropical storms that have come within 100 miles of Bermuda have made landfall.

The island is a renowned offshore financial center with sturdy construction, and given its elevation, storm surge is not as problematic as it is with low-lying islands.

Ernesto previously battered the northeast Caribbean, where it left hundreds of thousands of people without power and water in Puerto Rico after swiping past the U.S. territory as a tropical storm.

More than 245,000 out of 1.4 million clients were still without power more than two days after the storm. A similar number were without water.

"It's not easy," said Andrés Cabrera, 60, who lives in the north coastal city of Carolina and had no water or power.

Like many on the island, he could not afford a generator or solar panels. Cabrera said he was relying for relief only "on the wind that comes in from the street."

Ernesto is the fifth named storm and the third hurricane of this year's Atlantic hurricane season.

The National Oceanic and Atmospheric Administration has predicted an above-average Atlantic hurricane season this year because of record warm ocean temperatures. It forecast 17 to 25 named storms, with four to seven major hurricanes.