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.