Hawaiian hurricanes: Hardly common, but occasionally havoc-wreaking

Tropical depression (formerly tropical storm) Flossie, now exiting Hawaii, is a reminder that the 50th state is not immune from tropical storms and hurricanes.

Animation of tropical depression Flossie this morning. (NOAA)

Animation of tropical depression Flossie this morning. (NOAA)

Hawaii stretches from latitude 19° north to 22° north, roughly an area as wide as the belt from Jamaica across the southern half of Cuba. Yet, Hawaii sees far fewer hurricanes and tropical storms than places in the Caribbean at the same latitudes.

The Pacific Ocean water around Hawaii is generally a little cooler than the Caribbean Sea and often doesn’t supply the energy hurricanes need to thrive. Also, upper atmospheric winds over the central Pacific Ocean are more likely to be blowing from different directions than winds near the surface than over the Caribbean Sea. Such winds create wind shear that rips storms apart.

Nevertheless, Hawaii isn’t completely free of tropical cyclones. Since 1950, when reliable tropical cyclone records began, five hurricanes have caused serious damage and caused deaths in Hawaii.

Tropical storms and hurricane approach Hawaii from two directions. Roughly 70 percent, including Flossie, come from the eastern Pacific. The rest form in the Central Pacific Basin south of Hawaii between longitudes 140° and 180° west longitude.

Flossie formed roughly 1,000 miles southwest of Cabo San Lucas at the tip of Mexico’s Baja Peninsula at 8 p.m. on July 24. The NWS National Hurricane Center in Miami named the storm and provided forecasts until July 27 when Flossie moved west of 140° west longitude. It then became the responsibility the NWS’s Central Pacific Hurricane Center in Honolulu, which took over tracking and forecasting.

By far the worst storm on record to hit Hawaii was Hurricane Iniki, which was a 145 mph Category 4 hurricane that crossed the island of Kauai on Sept. 10-11, 1992. It had formed in the eastern Pacific basin and was roughly 470 miles south-southeast of the state when it recurved toward the north to hit Kauai. It killed six people and destroyed more than 1400 houses and seriously damaged another 5,000. The damage was estimated at $2.3 billion in 1982 dollars.  Most of the damage was on Kauai, but Oahu also suffered serious damage.

Satellite view of Hurricane Iniki (NOAA)

Satellite view of Hurricane Iniki (NOAA)

Hawaii’s other damaging storms since 1950 are:

Hurricane Dot, which came from the east, hit Kauai on Aug. 6, 1959 with sustained winds as fast as 81 mph. At the time Kauai’s economy was based on farming, not today’s tourist resorts, homes, and condos. Dot did an estimated $6 million in damage to the sugar, macadamia nuts, and pineapple crops. Four days before Dot hit Hawaii an Air Force hurricane hunter airplane had reported its winds were 150 mph or faster. Hurricane hunters no longer routinely fly out of Hawaii.

Hurricane Nina, which didn’t directly hit Hawaii—its center passed 120 miles west of Kauai— produced 82 mph wind gusts in Honolulu on Dec. 1, 1957. Its heavy rain caused damage on Kauai and Oahu islands, but high surf on Kauai’s southern shore was blamed for most of the estimated $100,000 damage in 1957 dollars.

Hurricane Estelle formed in the eastern Pacific and on July 21, 1956. It was a Category 4 hurricane with 132 mph winds, when it was 900 miles southeast of Hilo, Hawaii. Fortunately, by the time its center passed 133 miles south of Hawaii’s southernmost point on July 23 its strongest winds had weakened 40 mph, barely a tropical storm. Nevertheless, by that time the 15- to 20-foot waves Estelle had generated were crashing into Hawaii’s southernmost “Big Island” and the island of Maui, destroying at least five houses and damaging others, causing $2 million in damage.

Hurricane Iwa, which hit Hawaii on November 23,1982 produced an estimated $234 million in damage, making it the state’s most expensive hurricane until Iniki hit 10 years later. Iwa heavily damaged the islands of Kauai, Oahu, and Niihau with wind gusts faster than 120 mph, 30-foot waves, and 8 feet of storm surge on the southern coast of Kauai even though its center passed 25 miles north of Kauai. While Iwa was blamed for only four deaths, it destroyed or seriously damaged 2,345 buildings, leaving 500 people homeless. Damages were estimated at $312 million in 1982 dollars.

The NWS Central Pacific Hurricane Center in Honolulu tracks and forecasts all Central Pacific Basin storms and those from the eastern Pacific after they move west of 140° west longitude.

Tropical Cyclones west of 180° west longitude in the Western Pacific Basin and are called typhoons.  The U.S. Navy and Air Force Joint Typhoon Warning Center located at Joint Base Pearl Harbor-Hickman in Hawaii handles typhoon forecasting for U.S. military and civilian interests. Nations around the western Pacific also have their own typhoon forecasting centers.

Each of the three North Pacific Ocean basins have separate, rotating lists of names similar to the lists used for Atlantic Basin storms.  (Link: List of Pacific Ocean storm tropical cyclone names)

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