Not all storms move at the same speed but on average it can take at least 12 days for a storm to reach the U.S. if emerging from Africa. It depends on the atmospheric pattern that's in place.

There are over 3,700 miles from Cabo Verde in the far eastern tropical Atlantic to Key West, Fla. As you may imagine a tropical wave just emerging from Africa will take a long time to travel toward the Americas. If you add different atmospheric conditions that a storm might encounter as it intensifies as well as friction from land, it could make for a long journey.

So when you hear us talking about a storm for more than a week, it is likely because it was born as an African tropical wave, and we have been monitoring it since before being officially 'baptized'. Hang tight!