Ernesto could become 'major hurricane' this week; Puerto Rico braces for arrival

Editor's Note: This page is a summary of news on Tropical Storm Ernesto for Tuesday, Aug. 13. For the latest news on Ernesto as it moves across the Caribbean, view USA TODAY's story on the storm for Wednesday, Aug. 14.

Tropical Storm Ernesto strengthened and unloaded heavy rain over the northeast Caribbean islands as authorities in Puerto Rico and the Virgin Islands prepared for the arrival of hurricane conditions.

The storm is expected to become a hurricane Wednesday morning and "could become a major hurricane in a couple of days," the National Hurricane Center said in its 2 a.m. Atlantic Standard Time advisory on Wednesday when Ernesto was 80 miles northwest of St. Thomas and 40 miles north of San Juan, Puerto Rico.

The storm's center was forecast to pass the northeast and north of Puerto Rico through early Wednesday, according to the hurricane center. "Ernesto should then move over the western Atlantic later in the week and approach Bermuda on Friday," the center said.

Forecasters say Ernesto, the second named Atlantic storm in a week, could cause flooding and mudslides by dropping 4 to 6 inches of rain on the U.S. and British Virgin Islands, as well as 6 to 8 inches on southeastern Puerto Rico. Tropical storm conditions were forecast to continue spreading across the Virgin Islands, Puerto Rico, as well as Culebra and Vieques − islands that are part of Puerto Rico − through the overnight hours.

Ernesto developed into a tropical storm Monday night as it sped toward the northern Leeward Islands before passing near Guadeloupe and Montserrat early Tuesday. The storm strengthened and organized through the morning hours, bringing sustained winds of up to 60 mph as it barreled toward the Virgin Islands and 65 mph when closing in on Puerto Rico in the evening.

Puerto Rico Gov. Pedro Pierluisi canceled Tuesday's first day of class in public schools, activated the National Guard and announced the opening of hundreds of shelters across the island. The government of the U.S. Virgin Islands also closed schools Tuesday, and Gov. Albert Bryan Jr. urged residents to take the storm seriously.

LUMA Energy, the private operator of Puerto Rico's transmission and distribution system, said on X that it had activated its emergency operations and mobilized crews in anticipation of the storm. The power company also advised residents to brace for power outages.

Ernesto:Track where the storm is heading in the latest models

As a result of Ernesto's development, the U.S. and British Virgin Islands, Culebra and Vieques were placed under hurricane watches. "If you're in those areas, you need to go ahead and get prepared for a potential for hurricane conditions," NHC Deputy Director Jamie Rhome said during a livestream.

Sign up to get updates about current storms and weather events by location.

Increasing flight cancellations at Puerto Rico's top airport

The approaching storm is scrambling air traffic in and out of Puerto Rico, a U.S. commonwealth that's home to more than 3 million American citizens and a popular vacation destination.

Luis Munoz Marin International Airport in San Juan, the island's top flight destination, canceled 32 departing and 38 arriving flights Tuesday, the largest number of any airport in the world, according to the tracking website FlightAware.

Puerto Rico officials warn of power outages

Puerto Rico, which has a history of destructive storms, faced prolonged outages due to its fragile power grid in previous years.

In 2017, Hurricanes Irma and Maria slammed the island and destroyed its power grid. Over a million Puerto Ricans were left with unreliable power and outages lasted nearly a year in some areas.

Nearly five years later, Hurricane Fiona made landfall and conditions caused the entire island to lose power, USA TODAY previously reported. Strong winds had disrupted transmission lines, resulting in "a blackout on all the island," LUMA Energy said at the time.

In December 2022, Congress approved $1 billion in funds to improve and stabilize the grid in Puerto Rico.

Will Ernesto impact the US?

While the continental U.S. will largely be spared from the storm's heavy rain and winds, authorities have warned of dangerous rip currents and rough surf along the nation's Atlantic coast. Last year, all eight deaths directly tied to Hurricane Idalia were the result of large waves and rip currents.

The Coast Guard on Monday cautioned recreational boaters, fishermen, beachgoers, and water sports enthusiasts in the U.S. Virgin Islands and Puerto Rico to stay out of the water "due to deteriorating sea state conditions and dangerous rip currents associated with Tropical Storm Ernesto."

“We urge the public and the maritime community to stay safe and not underestimate the impacts of this storm,” Capt. Luis Rodriguez, Coast Guard Sector San Juan commander, said in a statement.

Start your morning informed: Sign up for USA TODAY's Daily Briefing newsletter.

Dangerous rip currents are a growing concern

Weather service offices between Florida and North Carolina are ramping up their warnings about potentially dangerous beach conditions, including hazardous rip currents, along the coast starting Friday as Ernesto moves by.

Strong swells will begin to reach North Carolina beaches by Friday and coincide with a higher-than-normal tide phase, said Erik Heden, a meteorologist in the state's Morehead City office. The impacts may linger into early next week as Ernesto moves away, Heden said.

A big concern is the potential for unsuspecting tourists to get caught in rip currents in the nice weather expected this weekend. "Other coastal impacts may include ocean overwash, erosion, and a generally higher-than-normal water level," Heden said.

Rip currents are powerful channels of water perpendicular to the shore that can pull swimmers quickly into deeper water. Officials say swimmers should never enter the water in red flag conditions. If caught in a rip current, swimmers are encouraged to avoid panicking and float or swim out of the current, then swim parallel to the shore and signal for help.

− Dinah Voyles Pulver

Why isn't Ernesto forecast to hit the US mainland?

Ernesto is not forecast to hit the U.S. mainland and is instead predicted to curve out to sea. This isn't unusual: Of all the tropical storms and hurricanes that form in the tropical Atlantic in a given year, only about three on average make their way to U.S. shores, according to the textbook Meteorology Today.

Because hurricanes don't move themselves, they are steered around by large weather systems and global winds. Most often storms are pushed northward around or along the western portion of a ridge of high pressure over the Atlantic, commonly known as a Bermuda High. If the high is located to the east, then hurricanes generally slide around the high’s western edge into the open Atlantic Ocean without making landfall, according to the University of Rhode Island. That's what's predicted to happen with Ernesto later this week, the National Hurricane Center said.

Sometimes, however, the high is located to the west and extends far enough to the south, in which case storms are blocked from curving north and forced to continue west, putting a large bulls-eye on Florida, Cuba, and the Gulf of Mexico.

Current hurricane season

Across the eastern U.S., residents and authorities are still recovering from former Hurricane Debby, a deadly storm that triggered dangerous floods from Florida to western New York and Pennsylvania. Last month, Hurricane Beryl – the earliest Category 5 Atlantic hurricane on record – was linked to over 20 deaths across Texas and the Caribbean.

Contributing: Doyle Rice and Dinah Voyles Pulver, USA TODAY; Reuters