Story highlights Irma is a storm that formed in the far eastern Atlantic

Such hurricanes are some of the largest and most intense

(CNN) Hurricane Irma is swirling in the Atlantic, posing a threat to parts of the Caribbean and denying forecasters a chance to catch their breaths after Hurricane Harvey.

On Sunday afternoon, Irma's center was about 790 miles east of the Leeward Islands, a group of islands in the West Indies that start east of Puerto Rico. Tropical-storm-force winds from Irma would most likely begin in the Leeward Islands on Tuesday night, and the storm is expected to be near the northern Leeward Islands by late Tuesday.

Hurricane watches have been issued for the 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 on Monday.

"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.

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