Hurricane Erin has strengthened to a Category 4 hurricane as it threatens to bring life-threatening surf and rip currents to the eastern coast of the United States. The rains caused by the storm are already beginning to hit the south-eastern Bahamas, and the Turk and Caicos Islands, where a tropical storm warning is in effect.

After exploding in strength at a historic rate this weekend, Hurricane Erin is now a sprawling Category 4 storm churning in the Atlantic. The storm’s enormous footprint is becoming the biggest concern as it threatens to drive life-threatening rip currents and towering waves toward the eastern US coastline and Bermuda.

Forecasters expect Hurricane Erin, one of the fastest rapidly intensifying storms in history, to bring flooding and dangerous currents as the Category 4 hurricane travels to the U.S. East Coast this week.