The characteristics of United States rainfall climatology differ significantly across the United States and those under United States sovereignty. Late summer and fall tropical cyclones bring precipitation which falls across the Gulf and Atlantic states. During the winter, and spring, Pacific storm systems bring Hawaii and the western United States most of their precipitation. Low pressure systems moving up the East coast bring cold season precipitation to the Mid-West and Northeast states, as well as Great Salt Lake and the Finger Lakes region. The snow to liquid ratio across the contiguous United States averages 13:1, meaning 13 inches (330 mm) of snow melts down to 1 inch (25 mm) of water.