Tropical Storm Dorian is expected to strengthen into a hurricane by Wednesday, forecasters said Sunday as the tempest barreled toward the Caribbean.

The eye of the storm, which was about 430 miles east-southeast of Barbados on Sunday afternoon, is already packing 40 mph winds and is expected to grow more fierce as it closes in on the Caribbean, according to the National Hurricane Center.

Officials in Barbados, St. Lucia and St. Vincent have already issued a tropical storm watch.

“Right now it’s a tropical storm and we are expecting it to strengthen close to or reaching hurricane intensity as it approaches,” said NHC meteorologist Michael Brennan.

“We are approaching the peak of the hurricane season,” he said, “so everybody in the Caribbean and along the U.S. South, Gulf and East Coast needs to be aware and follow these systems.”

Dorian is the named fourth tropical storm this hurricane season.

It’s projected path currently has it slamming into Puerto Rico on Thursday morning and continuing toward the island of Hispaniola at it veers Northwest and towards Miami.

Puerto Rico is still reeling from the damage done by Hurricane Maria in 2017, which killed more than 3,000 and caused more than $90 billion in damage.