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

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

South Florida is not expected to see direct impacts from Hurricane Erin, but rip currents and surf up to 6 feet, especially along Palm Beach, are expected.

Hurricane Erin won't hit the Carolinas directly, but coastal surf risks rise. Stay informed to keep beach outings safe as rip currents pose a threat.

Parts of North Carolina's Outer Banks are under mandatory evacuation orders, as the National Hurricane Center warns that Hurricane Erin could bring tall waves topping 15 to 20 feet.

Hurricane Erin is still headed north, slowly powering up the Atlantic. While on average a hurricane moves at 15 to 20 mph, Erin, a Category 4 storm, has been moving at 10 mph, sometimes slower, according to the National Hurricane Center.

Hurricane Erin is churning up the Atlantic, triggering coastal flood advisories at the NJ shore. How big will the waves get? 100 feet? What we know.