The rising motion associated with these upper lows lifts the trade-wind inversion, and the cold air aloft weakens or destroys the inversion altogether. When the trade-wind inversion disappears, deep cloud systems and flooding rains can occur, sometimes accompanied by thunder and lightning. In addition, the cyclonic circulation aloft can build down to the ocean surface, thereby setting the stage for Kona weather, an interruption of the trades. In fact, a few Kona storms each winter deliver half the annual rainfall in the drier areas of Hawaii. Five people died in the floodwaters.
Hurricanes are rare in Hawaii.
Only four have affected the islands since 1957, of which Iniki in 1992 was by far the most destructive. Iniki crossed the western end of Kauai in the early afternoon of September 11, destroying 2,000 homes and severely damaging 4,000 others. Five thousand power poles were blown down and numerous residents of Kauai were without power for one to two weeks. Iniki still ranks as the worst natural disaster in Hawaii. Remarkably, only two lives were lost.