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

A tropical storm warning means tropical storm conditions are expected somewhere within the warning area, and in this case, within 24 hours, the NHC said. Heavy rain is still expected across the Virgin Islands and Puerto Rico, with rainfall of 3 to 6 inches, with 8 inches in some isolated areas.

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

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.

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.