Hurricane Erin exploded in strength to a Category 5 storm in the Caribbean on Saturday, rapidly powering up from a tropical storm in a single day, the National Hurricane Center said.

Erin reached Category 5 status before weakening but has brought significant rain to the Virgin Islands and Puerto Rico.

Erin is the first hurricane to develop over the Atlantic this year, and meteorologists are closely tracking its path and forecast.

Officials in the northern Caribbean are warning of heavy rains and dangerous swells as Tropical Storm Erin approaches the region.

Erin, which quickly strengthened into a Category 5 storm on Saturday, is not expected to make landfall in the U.S., but experts remain on alert.

As of Wednesday afternoon, Tropical Storm Erin is churning in the Atlantic Ocean and moving toward the Caribbean, likely to become the season’s first hurricane, a storm with sustained winds above 74 miles per hour.