Hurricane Erin has weakened slightly to a Category 4 storm while positioned northeast of Puerto Rico and is on course to brush along the U.S. East Coast.

While a Gulf disturbance that moved into Texas on Friday seems to have run its course, Hurricane Erin in the western Atlantic intensifies.

Erin, the first hurricane of the season, exploded to a Category 5 hurricane Saturday, and despite fluctuations in intensity, the storm is remaining formidable this weekend. Here's where it could head in the week ahead.

Tracking Hurricane Erin, the first named storm of the Atlantic hurricane season, which weakened to a Category 3 storm early Sunday.

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

Erin is producing maximum sustained winds of 125 mph (205 km/h) and a central pressure of 940 mb. The storm is moving west‑northwest at 14 mph (22 km/h). Outer rainbands have been producing gusty winds and heavy rainfall across the U.S. Virgin Islands and Puerto Rico since Saturday night.

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

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.