Tropical Storm Ernesto could form soon in the Caribbean. Here's what the forecast says

More watches and warnings were issued across the Caribbean Monday as hurricane hunters set out to investigate a system expected to turn into a tropical storm.

The future Ernesto will bring heavy rain, flash flooding and other stormy conditions to Puerto Rico, the Virgin islands and a dozen other islands in the Caribbean this week, forecasters say. Ernesto would be the fifth named storm of the 2024 Atlantic hurricane season.

Forecasters expect the system will turn into a tropical depression Monday as it moves rapidly west across the Atlantic, toward the Caribbean. It’s forecast to turn into a tropical storm by the time it nears islands in the eastern Caribbean Sea late Monday or early Tuesday before approaching the U.S. and British Virgin Islands and Puerto Rico, according to the National Hurricane Center.

Several Caribbean islands, including Antigua, Barbuda, Saba and St. Eustatius, Guadeloupe and St. Maarten were put under tropical storm warnings Monday. Puerto Rico and the U.S. and British Virgin islands remain under a tropical storm watch, although forecasters say additional watches and warnings could be issued later across the Caribbean.

Based on Monday’s forecast track, the system is not a threat to Florida.

Here’s what to know:

Where is the system now and where is it going?

The system, which is moving rapidly west across the Atlantic, was about 525 miles east-southeast of Antigua and about 830 miles east-southeast of San Juan, Puerto Rico, early Monday, according to the hurricane center.

Even though the system remained disorganized early Monday and is continuing to be battered by easterly shear, forecasters expect it will strengthen into a tropical storm by the time it nears the Leeward Islands Tuesday. The forecast track shows it remaining at tropical storm strength as it approaches the U.S. and British Virgin Islands and Puerto Rico on Tuesday evening.

There is “still uncertainty on where the predominant center will eventually form, and this will affect where the system may track with respect to the Leeward Islands, the Virgin Islands, and Puerto Rico,” the hurricane center said.

The hurricane center’s forecast track shows it strengthening into a hurricane by early Thursday once it’s in the Atlantic’s open waters, to the north of Puerto Rico. NOAA hurricane hunters are investigating the system, the hurricane center said.

It has a high 90% chance of formation within the next two to seven days, according to the hurricane center.

What type of weather will the storm bring?

The hurricane center expects tropical storm conditions, including gusty winds and heavy rain, will be felt across portions of a group of islands in the eastern Caribbean Sea on Tuesday.

“Heavy rainfall may result in locally considerable flash flooding and mudslides in areas of the Leeward Islands by later today into Wednesday, and over Puerto Rico late Tuesday into Thursday,” according to the hurricane center’s forecast.

The system, which is being referred to as Potential Tropical Cyclone Five, is forecast to bring 4 to 6 inches of rain over portions of the Leeward Islands. For Puerto Rico, 3 to 6 inches of rain will be possible, with some areas seeing up to 10 inches of rain, according to the hurricane center. Eastern Hispaniola, the island shared by Haiti and the Dominican Republic, could see 2 to 4 inches of rain.

Storm surge, which is one of the most dangerous part of a system, is forecast to “raise water levels by as much as 1 to 3 feet above ground level for the eastern coast of Puerto Rico from San Juan to Guayama, including the islands of Culebra and Vieques and in the U.S. Virgin Islands, including St. Thomas, St. John, and St. Croix,” according to the hurricane center.

Watches and warnings

Tropical storm warning: St. Kitts, Nevis, Montserrat, Antigua, Barbuda, Anguilla, Guadeloupe, St. Martin and St. Barthelemy, Sint Maarten.

Tropical storm watch is in effect for: Puerto Rico, U.S. and British Virgin Islands, Vieques, Culebra