Hurricane Ernesto continued to bring torrential rains to Puerto Rico Wednesday afternoon as it moved away from the island after its strong winds left hundreds of thousands of people without power there and in the Virgin Islands.

The Category 1 hurricane had maximum sustained winds of 75 mph at 2 p.m. EDT, according to the National Hurricane Center. Its center was more than 200 miles northwest of San Juan, Puerto Rico, on Wednesday afternoon after passing over the Virgin Islands on Tuesday and then skirting Puerto Rico.

Strong winds extended far beyond its center, reaching gusts of over 120 km/h – hurricane force – in Puerto Rico and the U.S. Virgin Islands.

As a result, more than 700,000 homes in Puerto Rico – half of all homes on the island – were without power on Wednesday, according to LUMA Energy, the private company responsible for power transmission and distribution in Puerto Rico. The number of outages doubled within a few hours on Wednesday morning.

In the U.S. Virgin Islands, more than 46,000 customers were without power, according to PowerOutage.us, or about 92% of the island’s covered customers.

Nearly 6 inches of rain had fallen in Puerto Rico so far, and subsequent storm bands continued to dump rain Wednesday afternoon, causing flash flooding – particularly in eastern and southern Puerto Rico and the Virgin Islands.

Several flash flood warnings were still in effect for Puerto Rico on Wednesday afternoon.

According to the island’s water authority, heavy rains and flooding caused several rivers in Puerto Rico to overflow their banks and disrupted water filtration processes at several water treatment plants to varying degrees.

Due to these outages, more than 120,000 water customers – about 10% of all customers – were without access to drinking water as of early Wednesday afternoon, according to the island’s emergency portal.

Ernesto will reach the open Atlantic later Wednesday, where it is expected to strengthen into a major hurricane, but its power will still be felt in parts of the Caribbean for most of the day.

On the east coast of Puerto Rico, a storm surge caused water levels to rise by 30 to 90 centimeters early Wednesday. Life-threatening waves and backwash could pose a threat to life for anyone in the water through the weekend.

Ahead of the storm, Puerto Rico’s governor Pedro Pierluisi mobilized the National Guard and urged people to shelter in their homes. Public schools have been closed across the island and nearly 80 shelters have been opened.

Residents have also been warned to prepare for widespread power outages as the island’s fragile and aging power grid is still being repaired after being knocked out by Hurricane Maria in 2017.

Power outages are a daily nuisance for Puerto Ricans, many of whom have witnessed the laborious and slow efforts to modernize an electrical grid that remains highly vulnerable to natural disasters.

LUMA Energy said it had mobilized teams across the islands to respond to power outages. And LUMA President Juan Saca urged residents to report power outages as the utility may not be aware of all outages.

“Puerto Rico’s electrical system is not sufficiently modernized to detect power outages,” Saca said Tuesday, The Associated Press reported.

Where Ernesto goes next

Starting Wednesday, Ernesto will begin a gradual northward curve, moving away from the Caribbean into the open Atlantic waters, where it is expected to continue to strengthen.

Ernesto will become a strong Category 3 hurricane later this week and could maintain that strength or become a powerful Category 2 hurricane as it passes Bermuda this weekend. How hard the storm will hit Bermuda will depend on how close it gets to the tiny island, which is one-third the size of Washington, DC.

Bermuda will experience increased rain and wind impacts if the hurricane passes just west of the island as currently forecast. If Ernesto passes east of the island, the island may be spared more intense impacts.

Ernesto’s power is enhanced by very warm ocean waters – a result of global temperature increases due to fossil fuel pollution – and by minimal storm-disrupting winds aloft.

Ernesto will have widespread impacts later this week and this weekend, although its path lies somewhere over the open Atlantic.

The storm will churn up the sea hundreds of miles away and could cause dangerous rip currents along the east coast of the United States, the Bahamas and parts of the Caribbean through early next week.

Are more tropical problems ahead?

Apart from Ernesto, no tropical systems are currently expected in the Atlantic until at least early next week.

This short break in new development will not last long.

According to the Climate Prediction Center, the likelihood of another hurricane will increase again later in August and last until at least early September.

The most active time of the hurricane season is from mid-August to about mid-October, so the predicted increase in hurricanes is to be expected.

But tropical activity in the Atlantic is already faster than average. This basin usually doesn’t see its fifth named storm until late August and its third hurricane until early September.

Both have already happened, in what is expected to be a very busy season.

CNN’s Ella Nilsen and Amanda Musa contributed to this report.

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