National Geographic: Changes in the towering wall of vertical clouds surrounding the storm’s eye helped diminish Hurricane Earl’s intensity as it roared toward North Carolina’s Outer Banks (map) Thursday morning, meteorologists say. Earl was a very intense storm with winds exceeding 140 miles (225 kilometers) an hour as it moved northward along the U.S. East Coast. But as of Friday morning, Earl had diminished to a Category 1 hurricane with peak winds of about 85 miles (137 kilometers) an …