First, hurricanes require a stable atmosphere to develop and strengthen. It is estimated that a Hurricane needs somewhere around 40,000 to 60,000 vertical feet of stable atmosphere to form.
However, here in the Hawaiian Islands the atmosphere is very rarely stable. The prevailing trade winds blow consistently from East to West near the ocean surface, meanwhile and more importantly, the upper atmosphere winds known as the jet stream blow from West to East high above the Hawaiian Islands. This effect creates a phenomena known as wind shear. This wind shear keeps the atmosphere unstable around Hawaii, breaking up and weakening storms as they enter the central pacific.
Hurricanes also need warm water in order to build their strength. Again, the Hawaiian Islands and surrounding waters don’t cooperate. Hawaii is surrounded by deep, cool water, which typically weakens storms as they move away from the shallow warm water of the Eastern Pacific and into the colder water of the Central Pacific.
These factors help contribute to the low number of major hurricanes that have hit Hawai'i in living memory as well as helping Hawaiian Hurricane Group provide superior insurance rates. However, hurricanes are famously unpredictable and there is a very real possibility of the Hawaiian Islands being hit again by a powerful and devastating storm. Make sure your family and property are protected.