Hurricane Irma is churning west across the Atlantic, putting parts of the Caribbean on watch and prompting warnings for the US mainland to be prepared should the storm head that way.
Sunday evening Irma was traversing the ocean as Category 3 hurricane, with winds of 115 mph (185 kmh). It is expected to pick up strength over the next 48 hours, the National Hurricane Center (NHC) said.
Irma's center was about 625 miles east of the Leeward Islands, a group of islands in the West Indies that start east of Puerto Rico, the NHC said.
Hurricane watches have been issued for the Leeward Islands of Antigua, Barbuda, Anguilla, Montserrat, St. Kitts, and Nevis. Additional hurricane or tropical storm watches may come as soon as Monday for the British and US Virgin Islands and Puerto Rico.
"Hurricane conditions are possible within the watch area by Tuesday night, with tropical storm conditions possible by late Tuesday," the NHC said.
"Irma is expected to impact the northeastern Leeward Islands by the middle of this week as a major hurricane, accompanied by dangerous wind, storm surge, and rainfall impacts, along with rough surf and rip currents," the agency said.
Puerto Ricans warned
Irma is expected to remain a "dangerous major hurricane" through the week and could directly affect the British and US Virgin Islands, Puerto Rico, Hispaniola, Turks and Caicos, and the Bahamas, the agency said, warning that residents of the Lesser Antilles should monitor the hurricane's progress.
Puerto Rico Gov. Ricardo Rossello on Sunday asked the public to be aware of Irma's possibly trajectory and the impact the storm could have around noon Wednesday. The National Meteorological Service said the island could experience tropical storm winds and between 4 and 8 inches of rain.
Puerto Rico's State Agency for the Management of Emergencies and Disaster Management (AEMEAD) is monitoring Irma and has opened an information hotline.
Florida governor says be prepared
But it's too soon to know the impact Irma could have on the continental United States, where no warnings or watches are currently in effect, the agency said.
"Regardless, everyone in hurricane-prone areas should ensure that they have their hurricane plan in place, as we are now near the peak of the season," the hurricane center said.
In a series of tweets Sunday, Florida Gov. Rick Scott urged the state's residents to ensure their disaster supply kits were ready.
"FL knows how important it is to be prepared. Encourage your loved ones to have a plan ahead of any potential storm," Scott tweeted. "Disaster preparedness should be a priority for every Florida family."
Irma was designated a tropical storm Wednesday morning, and by Thursday afternoon, it had strengthened, with winds of 115 mph.
Irma is a classic "Cape Verde hurricane," a type of hurricane that forms in the far eastern Atlantic, near the Cape Verde Islands (now known as the Cabo Verde Islands), then tracks all the way across the Atlantic, CNN meteorologist Brandon Miller said.
Cape Verde storms frequently become some of the largest and most intense hurricanes. Examples are Hurricane Hugo, Hurricane Floyd, and Hurricane Ivan.