An interesting phenomenon known as the Fujiwara Effect can occur as one cyclone advances toward another. As the storms begin to interact, the weaker of the two may begin to orbit around the outer edge of the more dominant system. After one or two rotations, the stronger storm will either begin to absorb the other or send it spiraling in another direction.
Leslie and Michael are now about 1200 miles apart. If they happen to come to within 900-1000 miles of each other, the Fujiwhara Effect will take place.