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.

Hurricane Erin is a sprawling Category 4 storm churning in the Atlantic Monday after exploding in strength at a historic rate this weekend. The storm’s enormous footprint is becoming the biggest concern as it brings heavy rain and gusty winds to islands far from its center and threatens to drive life-threatening rip currents and towering waves toward the eastern US coastline and Bermuda,