SAN JUAN, Puerto Rico — 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 has strengthened into a hurricane as it approaches Puerto Rico and the Virgin Islands, bringing heavy rains that could cause flooding and landslides.

Hurricane Erin, now a Category 5 storm, with maximum sustained winds of 160-mph, is expected to continue strengthening.

Erin, the first hurricane of the season, is now a powerful Category 5 hurricane. Here's where it could head in the week ahead.

Heavy rains are forecast to start with the storm expected to become a major Category 3 storm over the weekend.

Hurricane Erin was expected to soak the Virgin Islands and Puerto Rico with heavy rain through the weekend before heading north up the Atlantic.

The NHC forecast advisory predicts Erin will continue westward today before bending west‑northwest tonight and through the weekend as a weakness develops in the subtropical ridge. Forecast positions show the storm moving from 16.

Tropical Storm Erin -- which is forecast to strengthen into the first hurricane of the Atlantic season by Saturday morning -- won't have a direct impact on the U.S., but it will bring dangerous rip currents to the East Coast.