Maps show Tropical Storm Ernesto’s path and forecast as it passes north of Puerto Rico

Tropical Storm Ernesto is expected to become a hurricane at some point Wednesday as it moves north of Puerto Rico, and could become a major hurricane in the next couple of days, the National Hurricane Center said. Ernesto was bringing “flooding rains” to parts of Puerto Rico and the Virgin Islands while approaching hurricane strength, forecasters said in an advisory out at 8 a.m. EDT.

Ernesto became the fifth named storm of the 2024 Atlantic hurricane season when it formed Monday along a fast-moving path to the Caribbean. The storm comes on the heels of Hurricane Debby, which lashed parts of the southeastern United States last week with disastrous flooding and brewed up a flash of severe weather that ultimately touched much of the East Coast. Ernesto isn’t expected to strike the U.S. mainland, the hurricane center said.

As of 8 a.m. Wednesday, forecasters said Ernesto had maximum sustained winds of 70 mph, just shy of the 74 mph needed for it to be classified as a hurricane, and was moving northwest at 16 mph. It was positioned about 125 miles northwest of San Juan, Puerto Rico, the hurricane center said.  Tropical-storm-force winds extended outward up to 150 miles from Ernesto’s center Wednesday morning — a sizable expansion from its 70-mile reach Tuesday morning.

Tropical storm warnings were effective in the U.S. and British Virgin Islands, Puerto Rico, Vieques and Culebra. An earlier hurricane watch for the British Virgin Islands was discontinued Wednesday morning.

Hurricane watches are issued when hurricane conditions are possible in a given area within 12 hours or so. Tropical storm warnings are issued when forecasters expect tropical storm conditions to impact an area within 36 hours.

Meteorologists said tropical storm conditions, primarily heavy rain, were already happening in the warning areas by Wednesday morning and expected them to continue for several more hours. 

“Heavy rainfall will result in locally considerable flash flooding and mudslides today over the Virgin Islands and into portions of Puerto Rico,” the hurricane center said at 8 a.m. In a previous advisory issued earlier in the morning, the center had forecast the possibility of “minor coastal flooding” in areas affected by onshore winds along the eastern coast of Puerto Rico, including the islands of Culebra and Vieques, and the U.S. Virgin Islands, including St. Thomas, St. John and St. Croix.

Not unlike Debby, which dumped devastating and, in some instances, historic rainfall on southeastern U.S. states last week, Ernesto’s primary threat was heavy rain, although less rain was forecast for this week compared with last week’s hurricane.

The hurricane center said the storm is expected to produce between 4 and 6 inches of rain over the U.S. and British Virgin Islands and up to 10 inches across southeastern Puerto Rico. There was “torrential rain” falling on eastern Puerto Rico Wednesday morning.

Ernesto was also forecast to drive ocean swells affecting parts of the Virgin Islands, Puerto Rico, the Dominican Republic, the Turks and Caicos and the Bahamas, before reaching the East Coast of the U.S. and Bermuda later in the week and into the weekend, the hurricane center said. Forecasters warned the swells would likely “cause life-threatening surf and rip current conditions.”