Civicane49's WunderBlog

Remembering Hurricane Iniki

By: Civicane49, 4:49 PM GMT on September 11, 2012

Hurricanes are fairly rare in Hawaii, but few of them have hit there in the past. One of them was Hurricane Iniki on September 11, 1992. It has been two decades since Iniki slammed Kauai, which is one of the Hawaiian Islands. This powerful hurricane struck Hawaii just weeks after Hurricane Andrew devastated Florida and Louisiana. Iniki had caused significant impact to the state of Hawaii, especially on Kauai. Since Iniki, however, no hurricanes have hit Hawaii. Nonetheless, Hawaii should still be fully prepared for these storms in the future, and I feel that Iniki is one of the infamous hurricanes to remember.


Figure 1. Satellite image of Hurricane Iniki making landfall on the island of Kauai. Image courtesy of NOAA.

Storm history
Like many hurricanes, Iniki, which is Hawaiian for sharp and piercing wind, had probably originated from a tropical wave that exited off the west coast of Africa on August 18, 1992, and the National Hurricane Center (NHC) began to track this wave. During the next several days, the wave moved generally westward across the Atlantic Ocean, the northern portion of South America, and Central America. During that time, it produced disorganized shower and thunderstorm activity. By August 28, the tropical wave entered into the Pacific Ocean, and it continued to move westward. By early September, however, the wave began to show signs of organization as it was situated in warm sea surface temperatures, which are favorable for tropical cyclone development.

On September 5, the wave became sufficiently organized that the NHC declared it as a tropical depression while the system was situated about 1,600 miles southwest of Baja California. The depression continued to move inexorably westward at about 10 mph under the influence of the southern periphery of the high pressure ridge. On early September 6, the depression crossed 140°W into the Central Pacific Hurricane Center’s (CPHC) area of responsibility, and the CPHC began to monitor the cyclone. Originally, the depression was forecasted to dissipate in the next day due to unfavorable atmospheric conditions expected; however, the conditions abruptly became favorable. As a result, the cyclone continued to gradually organize and strengthen. By September 8, the depression reached its surface winds of 40 mph; therefore, it strengthened into a tropical storm and was named Iniki. As the subtropical ridge moved towards the south, Iniki continued to intensify slowly and move westward at a little faster motion.

By September 9, the cyclone intensified to a hurricane with winds greater than 74 mph while it was located about 470 miles south-southeast of Hilo, Hawaii. At that time, the hurricane began to turn west-northwestward as it was approaching the western periphery of the subtropical ridge, which was situated north of Hawaii. This ridge typically keeps hurricanes away from the Hawaiian Islands by steering them south of the islands. This time, however, a large low pressure trough dug south just east of the International Date Line at 180°W, causing the ridge to weaken and move to the east. Consequently, Iniki turned northwestward and eventually northward to Hawaii, which caught forecasters off-guard. During the next day, reconnaissance plane reported that Iniki intensified to a major hurricane with winds of 115 mph and barometric pressure of 951 millibars as the cyclone was situated about 400 miles south of Lihue, Kauai. At that time, satellite image depicted that Iniki had developed a well-defined eye. In response to favorable conditions with warm sea surface temperatures and low wind shear, the hurricane strengthened further while it began to move northward.

On September 11, Iniki reached its peak intensity with maximum sustained winds of 145 mph and minimum central pressure of 938 millibars, making it a powerful Category 4 hurricane on the Saffir-Simpson Hurricane Scale. The intense cyclone was quickly approaching the island of Kauai, and at about 3:30 pm HST, Iniki made landfall between Waimea and Port Allen on the southwest coast of Kauai. During landfall, the estimated maximum sustained winds of the hurricane were recorded at 140 mph and central pressure was reported at 945 millibars, which these indicate that Iniki remained a Category 4 hurricane. Gusts were up to at least 175 mph. By roughly 4:10 pm HST, Iniki moved out of Haena on the north coast of the island. Thereafter, the cyclone began to rapidly weaken in unfavorable condition as it accelerated northward. By September 13, it weakened to a tropical storm. Later that day, Iniki lost its tropical characteristics by becoming an extratropical cyclone and then being absorbed by a low pressure trough as it was located roughly halfway between Hawaii and Alaska.


Figure 2. Track of Hurricane Iniki. Colors indicate different intensity based on the Saffir-Simpson Hurricane Scale. Image courtesy of Wikimedia Commons.

Damage and casualties of Iniki
Iniki was both the strongest and the most destructive hurricane to hit the state of Hawaii on record. It caused at least $1.8 billion (1992 USD) of damage. At that time, Iniki was one of the costliest hurricanes to strike the United States on record. Remarkably, only six people died as a result of the hurricane, but more than one hundred people were injured, and approximately 7,000 people were left homeless.

Most of the heavy damage was reported on Kauai, where the hurricane had hit. Iniki nearly destroyed everything on that island. It obliterated roughly 1,400 homes and damaged about 14,000 homes. Many buildings and homes were flattened or lost their roofs. Few buildings were left intact. Iniki’s powerful winds were primarily the cause of the extremely heavy damage. However, storm surge also caused severe damage to many condominiums, hotels, and homes along the south coast, especially on Poipu, where the greatest inundation occurred. Iniki had generated storm tides between 4.5 and 6 feet and wave heights between 20 and 35 feet. Telephone service, electric power, and radio stations were lost in the whole island. Even after four weeks since the hurricane hit, most of the power supply in the island still had not been restored. Crop damage was also widespread on Kauai. Sugar cane fields were knocked down. Tropical plants, including papaya and banana, were decimated. Nut and fruit trees, including macadamias, were damaged. Fortunately, there was no significant rainfall since the cyclone moved fairly quickly; however, if the hurricane had moved slower, the damage would have been far worse. Two deaths were reported on Kauai as a result of the storm. Offshore of Kauai, two Japanese citizens were drowned when their fishing boat capsized due to the hurricane.

Although Oahu was not directly hit, several buildings and homes on western Oahu were damaged mainly from waves and storm tides, which reached about 1.7 to 3 feet. Long periods of high waves seriously eroded the southwestern coast of the island. Overall, Iniki caused at least several million dollars of damage and two deaths on Oahu. Had Iniki tracked more north-northeastward and hit Oahu directly, both the damage and death toll would have been catastrophic. Other islands suffered minimal damage mainly from damaging surf.


Figure 3. Storm surge animation of Hurricane Iniki using NOAA's SLOSH (Sea, Lake, and Overland Surge from Hurricanes) storm surge model. The animation also shows the wind barbs of the hurricane. Wind barbs show both wind direction and speed. Green wind barbs represent tropical storm-force winds at 34 knots or greater. Red wind barbs represent hurricane-force winds at 65 knots or higher. Black wind barbs represent major hurricane-force winds at 100 knots or greater.


Figure 4. Flying debris and bent palm trees during the brunt of Hurricane Iniki on Lihue, Kauai. Photo by Bruce Asato, courtesy of the Honolulu Advertiser.


Figure 5. The wind damage after Iniki on Kauai. Image courtesy of Nick Galante.

Aftermath of Iniki
Iniki has changed the face of Kauai. During the day after Iniki hit, many people on Kauai were thankful to survive the powerful hurricane, but many were appalled for the significant damage left by the storm. Rescue and search groups, food, medical equipment and other items were arrived on that day to help survivors. Many residents were left without water and power for few weeks or months. The Coco Palms Resort, which was famous for the setting in Elvis Presley’s musical film Blue Hawaii in 1961, has remained closed since Iniki, and it is unknown when the hotel will ever be reopened. The hurricane had caused severe damage to that hotel. This and other damaged hotels have significantly affected the tourism industry on Kauai. In fact, the travel agents believed that Kauai looked like a disaster area since they have heard rumors that there were no water and electricity on that island even though the physical damage was repaired. However, the tourism industry has gradually been restored as most hotels, water supply, and electricity have been repaired after the storm. Another major impact from the hurricane was the wild chicken increase throughout Kauai. Iniki blew apart many chicken coops, which were used to house fighting chickens. Despite the fact that Kauai had extensive problems after the storm, residents of the island were surprisingly behaved; most people were not complaining and looting. Instead, many residents have helped others and cleaned up. A decade after the hurricane, the island of Kauai has not been restored completely, and people have still remembered the violence of the storm. Nevertheless, nearly everything on that island has been restored in the last few years.

Did Iniki made important lessons to the people of Kauai on being fully prepared for hurricanes? The answer from many officials was yes. According to Kauai’s public safety officials, the island was not actually ready for Hurricane Iniki, despite the fact that Kauai had faced three previous hurricanes since 1957. Those three hurricanes were Nina in 1957, Dot in 1959, and Iwa in 1982. Kauai had never encountered a powerful hurricane until Iniki. In fact, many buildings on that island were not strong enough to withstand a strong hurricane. Since Iniki, however, the building codes for hotels, condominiums and other buildings became more stringent; the enhanced buildings are made to withstand strong winds and all of the homes on the island are rebuilt or built with metal straps that create a bond from the roof to the foundation. Moreover, the people in Kauai are taking hurricane preparation seriously. Furthermore, the island’s communication system for emergency response has been hugely improved. Yet, the island still does not have sufficient amount of shelters that are able to withstand gale-force winds. Iniki will hopefully remind not only to the people on Kauai, but also other people on Hawaii for being aware of these storms, and how they will affect them. I believe Hawaii should be fully ready for future hurricanes similar to Iniki and other past significant hurricanes.

Other interesting facts on Iniki
On Kauai, filmmaker Steven Spielberg and his crews were forced to lose a day of filming Jurassic Park when Iniki arrived. Fortunately, Spielberg and 130 cast and crew members were safe from the hurricane. In the film, some of the storm scenes are real footage shot of Iniki.

Iniki is believed to have produced the highest measured wind speed of an Eastern Pacific hurricane on record. The Navy radar site at Makaha Ridge recorded a maximum wind of 227 mph from Iniki. However, this has been showed as an incongruity due to incorrect measurement of the device. Nevertheless, Dr. George Pararas-Carayannis does not utterly concur with that; he said that it might have been possible to reach such wind speeds from funneling effects. Additionally, Dr. Ted Fujita, a researcher at the University of Chicago, found that Iniki might have reached a wind speed of over 200 mph. He found that the hurricane had mini-swirls and microbursts within the edges of its eyewall. Mini-swirl is an intense whirlwind, not a tornado, whereas microburst is a sudden strong downdraft. They can be found in intense tropical cyclones and reach wind speeds of over 200 mph. Fujita recognized Iniki's damage patterns and debris, indicating that at least two mini-swirls and more than 20 microbursts had occurred on Kauai.

References
Bernardo, R. (2012, September 10). Iniki: 20 years after the storm. Honolulu Star-Advertiser, pp. A1, A7.

Central Pacific Hurricane Center. The 1992 Central Pacific Tropical Cyclone Season. United States National Oceanic and Atmospheric Administration's National Weather Service.

Fletcher, C. H., E. E. Grossman, B. M. Richmond, and A. E. Gibbs. (2002). Atlas of Natural Hazards in the Hawaiian Coastal Zone. U.S. Geological Survey, Geologic Investigations Series I-2761, pp 11.

Gardner, T. (2011, October 23). Kauai remains a popular film location. Los Angeles Times, pp. 2.

Kamen, A. (1992, September 13). Hawaii Hurricane Devastates Kauai. Washington Post, p. A01

NOAA's National Weather Service and U.S. Department of Commerce. (1993, April). Natural Disaster Survey Report: Hurricane Iniki September 6-13, 1992.

Pararas-Carayannis, G. (1993). HURRICANE INIKI IN THE HAWAIIAN ISLANDS September 11, 1992.

Sommer, A. (2002, September 8). The people of Kauai lived through a nightmare when the powerful storm struck. Honolulu Star-Bulletin.

TenBruggencate, J. (2002, September 10). Kaua'i's spirit endured Hurricane 'Iniki's test. Honolulu Advertiser.

TenBruggencate, J. (2007, August 2). Something's killing off Kauai chickens. Honolulu Advertiser.

Civicane49

Hurricane Hawaii

Updated: 5:19 PM GMT on September 11, 2013

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