Just days after Hurricane Harvey devastated parts of Texas and Louisiana, another storm, Hurricane Irma, has strengthened over the Atlantic Ocean, threatening to batter the Caribbean this week as "an extremely dangerous" Category 5 storm, the National Weather Service said.

With maximum winds near 180 mph, Irma is "the strongest hurricane in the Atlantic basin outside of the Caribbean Sea and Gulf of Mexico" ever recorded by the National Hurricane Centre, according to the weather service.