As a popular vacation destination, the Hawaiian Islands are well known for their predictable and relatively mild climate year-round. However, there are wide variations in weather depending on your exact location in the island chain. Additionally, there are some risks unique to airline operations caused by Hawaii's location and geography that you should be aware of before operating an aircraft in the 50th state. You may encounter trade winds and their associated weather, temperature inversions and their effects, volcanic eruptions, strong winds, heavy rain and tropical cyclones. The Hawaiian archipelago is located in the 0º-30ºN latitude range, which is the global circulation region where the northeast trade winds are found (Lester 7-5). These prevailing northeasterly winds cause unique precipitation patterns across the islands. The waters surrounding Hawaii average 25 to 30 inches of rain per year. However, Hawaii's orography and trade winds cause the islands to have up to 15 times more precipitation than the surrounding ocean (price 54-55). Warm, moist air from the Pacific is carried over the mountains to the windward of the islands, which then causes the air to rise, cool and condense to form clouds and rain. This effect often causes extreme precipitation of up to 9-11 m/year in many windward areas of northeast-facing islands (Giambelluca and Nullet 209). Along wind-exposed ridges in the northern parts of the islands, air lifting is common whenever the prevailing trade winds blow across the ridge. For glider pilots, this produces an advantageous ridge lift. For operators of powered aircraft, however, this can create turbulence over crests, especially when wind speeds are high. The so-called trad...... middle of paper ......her %20Patterns%20on%20Oahu% 20and%20Lania,%20Hawaii.pdf>.Lester, Peter F. Aviation Weather. Englewood, CO: Jeppesen Sanderson, 2007. Print.Macdonald, Gordon A. “Volcanism.” Atlas of Hawaii. [Sl]: Univ Pr of Hawaii, 1973. 36-38. Print."PHOG Maximum Wind Statistics (KAHULUI in USA MAUI ISL.) | Weather·Mobile." Aviation Weather for Pilots | Weather·Mobile. Network. December 05, 2011.Wind/PHOG-4>.Price, Saul. "Climate." Atlas of Hawaii. [Sl]: Univ Pr of Hawaii, 1973. 53-59. Print."Subtropical High (meteorology) - Britannica Online Encyclopedia." Encyclopedia - Encyclopedia Britannica online. Network. 05 December 2011.571157/subtropical-high>."Vog: a volcanic danger." USGS Hawaiian Volcano Observatory (HVO). 29 May 1996. Web. 05 December. 2011. .