SAN JUAN, Puerto Rico (AP) — 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. While the compact hurricane’s center wasn’t expected to hit land, it threatened to dump flooding rains as it continued to grow larger.

Heavy rains were forecast to start late Friday in Antigua and Barbuda, the U.S. and British Virgin Islands and southern and eastern Puerto Rico.

Hurricane Erin has strengthened to a Category 5 Atlantic hurricane, according to a special update from the National Hurricane Center. The storm has winds of 160 mph with even higher gusts. Heavy rainfall continues for the Northern Leeward Islands and Puerto Rico.