By Karl Heisler (October 13, 2017, 5:16 PM EDT) -- A trifecta of powerful hurricanes in the U.S. and Caribbean has already led to catastrophic devastation, and the 2017 season is not over yet. The first, Hurricane Harvey, was the first major (defined as Category 3+) hurricane to make landfall in the U.S. in well over a decade. Its slow descent on Texas contributed to the highest rainfall in Houston's recorded history. By some accounts, Harvey will become the second most costly natural disaster in U.S. history, bested only by Hurricane Katrina in 2005. The second, Hurricane Irma, charted a deadly course that took it along much of the Caribbean island chain, decimating Antigua and Barbuda as a Category 5, then on to Saint Martin and the Virgin Islands, before making landfall on the Florida Keys as a Category 4. Irma was one of the strongest Atlantic hurricanes by wind speed on record, having sustained 185 mph winds for a day-and-a-half. By comparison, the average wind speed for an F3 tornado ranges from 158-206 mph. The third, Hurricane Maria, created the worst natural disaster in the history of Dominica. Maria then moved on to cause prolific damage to Puerto Rico, destroying its entire power grid. Parts of the island may be dark for months. All told, the trifecta claimed at least 250 lives, with unofficial cost estimates exceeding $250 billion....