Complex sentence: It is also the fourth Atlantic hurricane of 2017 to make landfall anywhere in the United States or one of its territories; such a quartet has not occurred since 2005 and became the first tropical cyclone to make landfall in the state of Mississippi since Hurricane Katrina.
Split into simpler sentences: It is also the fourth Atlantic hurricane of 2017 to make landfall in the United States or one of its territories; such a quartet of landfalls has not occurred since 2005. In addition, Nate bwas the first tropical cyclone to move ashore in the state of Mississippi since Hurricane Katrina.