Hurricane Erin pelted parts of the Caribbean and was forecast to create dangerous surf and rip currents along the U.S. East Coast this week.

U.S. shores are unlikely to see a direct hit, but a strong offshore hurricane can produce massive and dangerous waves well away from its center.

After briefly weakening, Hurricane Erin has re-intensified into a Category 4 hurricane with sustained winds of 130 mph, according to the National Hurricane Center.

Hurricane Erin was downgraded to a Category 3 hurricane early Sunday as a tropical storm warning was issued for the Turks and Caicos Islands and winds and heavy rains whipped the Virgin Islands and Puerto Rico.

Erin, moving near the Leeward Islands, strengthened into a hurricane on Friday morning and is expected to pass north of Puerto Rico this weekend, the National Hurricane Center said.

A westward-moving tropical wave could produce an area of low pressure in the tropical Atlantic late in the week of Aug. 18, the hurricane center said on Aug. 16. The center shows a 20% chance of storm formation over the next week.

Tropical Storm Erin is approaching Puerto Rico and the Virgin Islands, bringing heavy rains that could cause flooding and landslides