Additional strengthening is expected on Monday as Hurricane Erin is forecast to “remain a large and dangerous major hurricane through the middle of this week,” the National Hurricane Center said.

The Outer Banks in North Carolina are under evacuation warning as Hurricane Erin whips up potentially 20-foot high waves and flooding along the east coast.

Hurricane Erin was a Category 4 storm again Monday morning and is expected to grow even larger and stronger, according to the latest advisory from the National Hurricane Center. Although Erin is forecast to move north between the U.S. and Bermuda, life-threatening surf and rip currents are likely across the Atlantic coast from Florida to Canada.

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.

Erin is the first hurricane to develop over the Atlantic this year, and meteorologists are closely tracking its path and forecast.

Coastal flood and beach erosion are also possible this week as Hurricane Erin passes far off the Jersey Shore.