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.

An Atlantic disturbance now has a 50 percent chance of cyclone formation, according to the National Hurricane Center.

A tropical disturbance along the Gulf could develop into a depression before moving into South Texas and northeastern Mexico Friday evening. Any development into a depression would likely be "short-lived," the National Weather Service said.

Hurricane Erin strengthened into a Category 4 storm as U.S. officials warned of dangerous rip currents expected this week.

Erin became one of the earliest Category 5 hurricanes on record on Saturday. The storm will lash parts of the northern Caribbean on Sunday and Monday.