The floodwaters from Hurricane Harvey have yet to recede in Texas and Louisiana, but weather forecasters are already warily eyeing another storm that is rapidly intensifying in the tropical Atlantic Ocean — and could threaten the U.S. next week.  Hurricane Irma, which was upgraded to a Category 3 storm on Thursday afternoon — and is likely to become a

high-end Category 4 or 5 beast of a storm — is moving west over the open ocean about 720 miles west of the Cabo Verde Islands. On its current track, Irma is forecast to begin affecting the Leeward Islands on Tuesday, with Puerto Rico, the Bahamas, and possibly the mainland U.S. in its sights after that.There are a few factors that worry hurricane forecasters more about this storm when compared to the myriad other tropical storms and hurricanes that tend to form in the Atlantic.  MORE