The storm is expected to remain over open waters and move north-northeast of islands including Antigua and Barbuda, the U.S. and British Virgin Islands and Puerto Rico, according to the National Hurricane Center in Miami.

Tropical Storm Erin has begun to strengthen and is expected to reach major hurricane intensity this weekend as it tracks just north of the Caribbean islands, where it could bring rain, gusty winds and high surf.

Tropical Storm Erin is on track to begin strengthening in the next day or so, likely to hurricane status as soon as Friday. The National Hurricane Center’s latest forecast keeps the storm north of Puerto Rico and the Virgin Islands,