Hawaii’s Hurricane History

In August of 1994, Hurricane John became the most powerful hurricane in Central Pacific history as it passed south of the Hawaiian Islands.

In August of 1994, Hurricane John became the most powerful hurricane in Central Pacific history as it passed south of the Hawaiian Islands (the Big Island is visible at top center). At peak intensity, the category 5 storm had surface winds of 175mph and gusts in excess of 200mph (CPHC, 1994).

Meteorologists once believed that the Hawaiian Islands were largely protected from hurricanes due to their unique position in the Central Pacific Ocean. Despite residing entirely within the tropics, the island chain is well north of the Intertropical Convergence Zone and within close proximity to an area of cool water which inhibits tropical cyclone development. A semi-permanent high pressure ridge north of the state also helps protect the islands from storms that deviate from the hurricane belt to the south. Additionally, massive shield volcanoes in excess of 13,000ft on the Big Island appear to act as natural buffers against hurricanes traveling from the Eastern Pacific. The influence of the island’s topography was widely noted following the rapid decay of several notable hurricanes, including Hurricane Jimena in 2003 and Hurricane Flossie in 2007.

In general, Hawaii very rarely experience significant affects from tropical cyclones beyond large surf. Full-fledged hurricane force winds (disregarding mountainous locations) have only affected the islands on three occasions. Historical records indicate that Kauai is by far the most vulnerable major island to hurricane impacts. The island of Oahu, where 70% of the state’s population resides, is the second most vulnerable location in the state due to its proximity to Kauai. The other islands, with the exception of the southern tip of the Big Island, have largely escaped serious damage since official record keeping began in 1950. It is likely, however, that every area of the state has been impacted by hurricanes over a wider time scale.

Below is a list of tropical cyclones that have seriously impacted the state since 1950. Storms that caused damage solely through large surf, such as Hurricane Estelle in 1986, are not included.

August, 1950 – Hurricane Hiki

Hurricane Hiki was the first operationally verified tropical cyclone to affect the Hawaii. The unusually small hurricane brought tropical storm force winds to the northern coasts of several islands. Above is a creative representation of the storm as it passes north of Kauai.

Hurricane Hiki was the first operationally verified tropical cyclone to affect the Hawaiian Islands. The unusually small hurricane brought tropical storm force winds to the northern coasts of several islands. Pictured is an illustration of the storm north of Kauai. Reconnaissance flights found that the storm’s eye was filled with clouds and approximately 20 miles wide (CPHC, 2013).

□ In 1950, the Joint Hurricane Warning Center began implementing a naming scheme for tropical cyclones in the Central Pacific. In August of that year, a tropical storm was identified southeast of the islands. The “immature storm” crossed several shipping lanes and strengthened despite passing through generally unfavorable waters east of the Big Island. A reconnaissance flight was sent to investigate the approaching storm, and the data indicated that the system was a full-fledged tropical storm with surface winds in excess of 50mph (CPHC, 2013). The system was given the name Hiki, the Hawaiian conversion of the military name Alpha. Gale warning were posted for the western islands as large waves began to crash onto the Hilo coastline (Star Bulletin, 1950).

On August 15th, Tropical Storm Hiki’s center passed approximately 100 miles north of the Big Island. The storm had an unusually small wind-field, so only minor damage was reported along the northern coastline (Star Bulletin, 1950). Winds were strong enough to fell a power-line in Kohala, however, and a 58-year old man was killed after coming into contact with a live wire. The system continued to intensify as it skirted past the island chain and attained hurricane intensity north of Molokai on August 16th. Parts of Oahu encountered tropical storm force winds, and minor power outages from downed tree branches were reported in Kaneohe and Manoa Valley (Star Bulletin, 1950). On the evening of August 15th, Hurricane Hiki came within 100 miles of Kauai. Sustained winds greater than 35mph and torrential rains battered the island. A total of 253 people were evacuated when a nighttime flash-flood caused the Waimea River to burst its banks. A wind gust of 68mph was recorded at Kilauea Lighthouse on Kauai’s northern coast, the highest terrestrial gust reported in the storm.

Hurricane Hiki was the first verified tropical cyclone to affect Hawaii.

Newspaper articles on Hurricane Hiki showed the eye of the storm passing closer to the islands than the current official track.

A high pressure ridge north of Hawaii slowed Hurricane Hiki’s forward movement on August 16th and began pushing its center to the southwest. Although the storm never made landfall, Kauai experienced the outer edges of Hurricane Hiki for more than four days. A weather station on the slopes of Mt. Waialeale recorded the heaviest rainfall ever associated with a tropical cyclone in US history. A total of 52 inches of rain was reported, with the majority of the precipitation falling on August 16th and 17th. Since the rain gauge had to be manually emptied every 24 hours, the container overflowed twice and likely failed to measure all of the precipitation (CPHC Archives).

Hiki maintained hurricane intensity for four days and had maximum surface winds of 85mph. Unlike the majority of tropical cyclones that have caused damage in Hawaii, Hurricane Hiki tracked north of the islands and strengthened despite passing within 150 miles of the Big Island’s tall mountain peaks. While hurricanes affecting the islands’ northern coasts are rare, a similar but more destructive tropical cyclone in 1871 may have brought hurricane force winds to the Big Island and Maui.

Hurricane Hiki intensified as it travelled north of the island chain, eventually reaching hurricane strength just off the coast of Kauai. Torrential rainfall caused the Waimea river to overflow its banks, damaging dozens of homes.

Star Bulletin image of flooding in Waimea Valley on Kauai.

December, 1957 – Hurricane Nina

Hurricane Nina was a large, late-season tropical cyclone that brought wind gusts in excess of 80mph to Kauai and Oahu. Above is a creative representation of what the system may have looked like at closest approach to the islands.

Hurricane Nina was a large, late-season tropical cyclone that brought wind gusts in excess of 80mph to Kauai and Oahu. Pictured is an illustration of the storm at closest approach to the islands. According to reconnaissance flights, the storm had a cloud-filled eye and spawned unusually large ocean waves in excess of 50ft.

□ On November 29, 1957, a late-season tropical cyclone developed only a few hundred miles north of the equator.  A weather station on Palmyra Island recorded a peak gust of 70mph as the storm passed over the area and tracked to the north. On November 30th, a reconnaissance flight determined that the system was of hurricane intensity and centered 500 miles north of Palmyra Island, where squally weather was still occurring (CPHC, 1957). The storm, which was given the name Nina, was forecast to continue northward towards the Hawaiian Islands. Gale warnings were issued for the islands of Niihau, Kauai and Oahu.

Hurricane Nina began curving away from the islands and made an abrupt turn to the west while centered 120 miles east-southeast of Kauai. A reconnaissance flights found that Hurricane Nina had a cloud-filled eye and massive seas that were so large, according to one pilot, that “nothing but a huge ship could live in that wild stuff” (Star Bulletin, 1957). Despite never making landfall, the category 1 storm brought hurricane force wind gusts and heavy rain to the islands of Kauai and Oahu. The most severe conditions occurred on Kauai, where more than 1,400 people were forced to take shelter at evacuation centers (Star Bulletin, 1957). An anemometer at Kilauea Lighthouse recorded a peak gust of 92mph at 8pm on December 1st (Star Bulletin, 1957). The winds shattered windows and uprooted trees across the island. On Kauai’s southern coast, massive 35ft waves severely damaged more than a dozen homes. Additionally, 20.4 inches of rain fell in 14 hours in Wainiha, resulting in a river flood which damaged a twin-span bridge (Star Bulletin, 1957). West of Kauai, a 43ft sampan capsized in stormy seas, resulting in three fatalities.

Hurricane Nina was the first storm in modern history to bring hurricane force wind gusts to the Hawaiian Islands.

Hurricane Nina was the first tropical storm in modern history to bring hurricane force wind gusts to the Hawaiian Islands. In the above image, a residence a mile north of Honolulu International Airport was crushed by a neighboring home’s roof.

Oahu was farther from the center of the storm but still experienced damaging winds. Hundreds of homes and businesses were damaged by winds across the island, including more than a dozen homes that were unroofed. Gusts of 70mph buffeted the southern half of the island, and Honolulu International Airport experienced a record gust of 82mph (Star Bulletin, 1957). Four concrete light posts in Waikiki were knocked down onto Ala Wai Boulevard and several show-windows in downtown Honolulu were blown out (Star Bulletin, 1957). One death occurred on Oahu when a man was electrocuted by a fallen power line (Star Bulletin, 1957).

Hurricane Nina travelled westward and away from the state on December 3rd, leaving behind three direct fatalities and at least $4 million (2012 dollars) in damage. The storm was the last of three hurricanes to come within close proximity of the state in the 1957 season, one of the most active in recent history.

The outer rain-bands of Hurricane Nina led to periods of intense winds across Oahu, damaging hundreds of homes.

The outer rain-bands of Hurricane Nina led to periods of intense winds across Oahu, damaging hundreds of homes (Star Bulletin, 1957).

August, 1958 – Unnamed Tropical Storm

The most significant tropical system to impact the state of Hawaii without attaining hurricane intensity made landfall on the Big Island in 1958. Pictured is a recreation of the storm at landfall utilizing a satellite grab of Tropical Storm Flossie.

The most significant tropical cyclone to impact the state of Hawaii without attaining hurricane intensity made landfall on the Big Island in 1958. Pictured is an illustration of the storm at landfall utilizing a satellite image of Tropical Storm Flossie in 2013.

□ One of the most significant yet forgotten tropical cyclones in Hawaiian history formed east of the Big Island in August of 1958. No records exist of the storm’s formation, so the official track has the system suddenly developing only a few miles offshore. According to the NHC database, the storm made landfall on the Hamakua coastline with sustained winds of 50mph on the evening of August 7th. Heavy rain and gusty winds began affecting Hilo in the predawn hours. Strong crosswinds interrupted operations at Hilo Airport, and one man died when a small plane crashed in the midst of the storm (Star Bulletin, 1958). The Big Island’s complex topography led to great variability in surface winds – some areas experienced sustained winds over 55mph while other locations encountered only breezy conditions. Damage patterns indicated that wind gusts in excess of 85mph occurred in some vulnerable areas (CPHC, 2013).

The mountain town of Waimea suffered heavy damage from high winds and flooding rains. At top right, a tree crushed a police car in Hilo, injuring a passanger inside. At bottom right, a fallen tree in Kailua-Kona.

The town of Waimea, which rests 2,500ft above sea level on Kohala Mountain, may have experienced the most severe conditions during the storm. Torrential rain caused extensive flooding in town and one woman was injured when high winds blew a tree onto her home. In Hilo, high winds toppled a 50ft pine tree onto a police cruiser, injuring a passenger (top right). In Kailua-Kona, winds uprooted trees and caused some property damage (bottom right).

Tropical storm force conditions affected a large portion of the island. In Honokaa, a large garage was ripped from its anchorage and moved several feet by high winds (Tribune Herald, 1958). The town of Waimea, located on an elevated saddle between Mauna Kea and Kohala Mountain, was buffeted by wind gusts in excess of 55mph and flooding rains. Cars stalled as water gushed down Mamalahoa Highway, and “roads were deeply rotted or washed out” along the mountain slopes (Star Bulletin, 1958). Farther south in Kona, wind gusts reportedly reached up to 75mph, snapping Keawe trees and sending outdoor patio furniture tumbling through the streets (Tribune Herald, 1958).

The tropical storm traversed the Big Island in only a few hours and re-entered the ocean just after midnight. While the official track indicates the storm weakened into a tropical depression, gale force winds were recorded at several locations on August 8th. Gusts over 55mph affected portions of Maui, Lanai, Molokai and Oahu, and sustained winds of 60mph with gusts to 75mph were recorded on the summit of Haleakala (Star Bulletin, 1958). Heavy rains fell over all of the major islands, causing a damaging landslide on Oahu. On August 9th, the weakening tropical depression dissipated 130 miles south of Niihau.

A tropical storm in 1958 made landfall near Hilo on the Big Island, the only such storm to do so since 1950. On Oahu, heavy rainfall led to a landslide on Tantalus. (Star Bulletin, 1958)

The 1958 tropical storm brought stormy conditions to the majority of the state. Heavy rainfall led to landslides on Tantalus on Oahu, destroying a road and several utility poles (Luke, 1958). The 1958 storm, along with Hurricane Iselle in 2014,  are the only tropical cyclone to make landfall on an island other than Kauai since modern record keeping began in the Central Pacific. Both storms struck the east coast of the Big Island as tropical storms. 

August, 1959 – Hurricane Dot

Hurricane Dot passed 90 miles south of the Big Island as a category 4 hurricane before turning to the northwest and making landfall on Kauai with winds of 90mph. Pictured is an illustration of the storm on the evening of August 6th.

Hurricane Dot passed 90 miles south of the Big Island as a category 4 hurricane before turning to the northwest and making landfall on Kauai with winds of 90mph. Pictured is an illustration of the storm just after midnight on August 5th. Reconnaissance flights determined that the hurricane had an unusually large eye, ranging between 35 and 40 miles in diameter.

□ The specifics surrounding the development of Hurricane Dot remain unknown. The system likely formed in late-July but was not officially documented until August 1st, when a ship reported hurricane force winds approximately 950 miles east-southeast of the Big Island. On August 3rd, the first reconnaissance flight intercepted Hurricane Dot and reported estimated surface winds of 150mph, making the storm a powerful category 4 hurricane. The storm’s central pressure remained unusually high in relation to its winds, never falling below 952mb during flight intercepts. One mission reported sustained winds of 160mph and a central pressure of 966mb (CPHC Archives, 2013).

Radar view of Hurricane Dot the evening of August 4th as captured by a US Air Force reconnaissance flight. The image is superimposed over a map of the storm's location.

Radar view of Hurricane Dot on the evening of August 4th as captured by a US Air Force reconnaissance flight. The image is superimposed over a map of the storm’s likely location.

Hurricane Dot maintained category 4 intensity as it tracked westward towards the Hawaiian Islands. On August 4th, models suggested that the hurricane would brush past the Big Island and remain south of the other islands (Star Bulletin, 1959). Gale warnings were issued for the Big Island, and the outer rain-bands of the storm began affecting the coastline after sunset on August 4th. Unlike other hurricanes that have followed similar tracks, Hurricane Dot did not weaken as it came under the influence of the Big Island’s towering mountain peaks. The storm’s center came within 90 miles of South Point, bringing tropical storm force conditions to a large portion of the island.

Sustained winds of 60mph with gusts to 85mph were recorded at South Point in the early morning hours. Journalists at a station in South Point later reported that their bunker was buffeted by high winds that snapped a radio antenna and nearly ripped a door from its hinges (Star Bulletin, 1959). Farther north, heavy rains flooded streams and waterfalls near Hilo (Star Bulletin, 1959). Additionally, massive 40ft waves damaged roads and agricultural buildings along the sparsely populated southeast coast (Star Bulletin, 1959). As the storm’s eye travelled past the island, huge swells propagated northward towards the West Hawaii shoreline. Waves up to 35ft pummeled the populated Kona coast, damaging hundreds of beachfront properties. The famed little grass shack at the Kona Inn was swept out to sea, and several hotel pools were deemed “total losses” (Star Bulletin, 1959). On Maui, giant waves damaged coastal property and a gust of 52mph was recorded at the Kahului airport (Star Bulletin, 1959).

High waves crash onto Alii Drive in Kailua-Kona. Waves of 35ft were recorded on the normally calm southwestern shores of the Big Island, breaking far offshore in a manner not seen before in living memory.

Thirty-five-foot waves were recorded on the normally calm southwestern shores of the Big Island. Properties along Alii Drive (pictured above) experienced varying degrees of damage. According to local residents, the storm waves broke far offshore in a manner never seen before (Star Bulletin, 1959).

Hurricane Dot’s winds dropped to 115mph as the storm executed an unexpected turn to the northwest. In the early morning hours of August 6th, tropical storm force winds began to affect parts of Oahu. A gust of 63mph was recorded at the Honolulu Airport around noon. Thirty-foot waves pounded against the entrance to Honolulu harbor, leading to its closure at 1pm (Stewart, 1959). Damaging winds affected most of the island but the most severe affects were reported on the exposed Wai’anae coastline, where several homes were completely unroofed (Black, 1959).

Updated forecasts predicted that Hurricane Dot’s center would pass through the Kauai Channel. The eye of the storm, however, passed directly over the island of Kauai on the night of August 6th with sustained winds of 90mph. Winds across the island began increasing rapidly around 4pm, and the full fury of the storm reached Lihue around sunset. The first half of the storm brought hurricane force winds to much of the island, leveling poorly built structures and felling thousands of trees. Forty-foot waves filled with debris from swollen rivers pounded Kauai’s southern coast, flooding the Coco Palms Hotel with more than 4ft of wind driven surge (Star Bulletin, 1959). Kilauea Lighthouse reported sustained winds of 81mph with a peak gust of 103mph (CPHC Archives, 1959).

A beach in Poipu was inundated by Hurricane Dot's storm tide and left covered in debris.

A beach in Poipu was inundated by Hurricane Dot’s storm tide and left covered in debris.

At 7:15pm, the storm’s 40-mile wide eye reached the island. A yacht in Hanlei Bay reported seeing a “bright starlit sky,” indicating Hurricane Dot’s eye was clear. An hour later, the back eyewall passed over the island, though it was reportedly less fierce than the first half of the storm. Just after midnight, the skies cleared above Kauai as Dot weakened back to a tropical storm and tracked off to the west-northwest. In its wake, the storm left approximately $56 million in damage (adjusted for inflation) across the state, primarily as a result of agricultural losses on Kauai. A similar storm today would likely cause over $1 billion in damage.

High winds from Hurricane Dot destroyed hundreds of buildings on Kauai.

High winds from Hurricane Dot destroyed hundreds of buildings on Kauai.

November, 1982 – Hurricane Iwa

Hurricane Iwa was perhaps the largest hurricane to ever directly affect the island chain. Despite passing just west of Niihau, the storm caused severe damage on the islands of Kauai and Oahu.

Hurricane Iwa was the second most destructive tropical cyclone in Hawaiian history. Despite passing just west of Niihau, the storm caused severe damage on the islands of Kauai and Oahu.

□ Amidst a powerful El Nino episode in 1982, an unusual late-season tropical storm developed far southwest of the Hawaiian Islands. The system tracked slowly northward and became Hurricane Iwa on the evening of November 22nd. The slow-moving system rapidly gained forward speed as it interacted with strong upper-level winds, causing the storm’s path to shift towards the islands of Niihau and Kauai. Hurricane Iwa’s sustained winds peaked at 90mph before gradually weakened as the storm rapidly approached the state. On November 23rd, the storm’s center passed only 25 miles west of the Napali Coast. Despite never making landfall, the exceptionally large storm caused severe damage to the western half of the state.

Hurricane Iwa battering Poipu, Kauai, with 35ft waves and wind gusts in excess of 90mph.

Hurricane Iwa battering Poipu, Kauai, with 35ft waves and wind gusts in excess of 90mph. While the storm’s sustained winds decreased to 80mph upon closest approach to the state, the system’s rapid forward pace increased the wind velocity over the islands.

Due to the Hurricane Iwa’s exceptional forward speed of 40mph, conditions within the dangerous right-front quadrant of the storm were intensified but of decreased duration. On Kauai, sustained winds averaged approximately 60 to 75mph but varied greatly due to local topography. In Poipu, giant waves and a six-foot storm surge completely destroyed dozens of oceanfront properties. In Lihue, hundreds of buildings were damaged and several businesses were destroyed by high winds. The most intense winds documented on the island occurred on the northern coast in Princeville, where peak gusts may have reached 120mph (Chiu, 1983).

Hurricane Iwa’s unusually large wind-field also brought damaging winds to Oahu. Most of the island experienced hurricane force wind gusts, and variations in local topography led to significantly stronger winds in downslope areas. The most intense winds on Oahu occurred primarily in a 40 minute period in the early evening as a heavy squall line passed over the island, but sustained winds in excess of 40mph affected the island for seven hours (Chiu, 1983). Honolulu Airport recorded winds of 49mph with a peak gust of 84mph (adjusted to 46mph and 81mph at 30ft elevation). Winds in the central valley were higher, with sustained readings averaging around 60mph. A dozen large warehouses at Schofield Barracks were damaged or destroyed. The most intense winds reported on the island occurred on the northern slopes of the Ko’olau Mountains. A US Air Force station in Kaneohe recorded sustained winds of 69mph with a peak gust of 112mph, the highest gust reported on Oahu (Chiu, 1983). Large waves and a modest storm surge destroyed homes in Wai’anae and flooded the streets of Waikiki. One seaman was killed when a Navy destroyer was struck by a large wave just outside of Pearl Harbor (CPHC, 2013).

Hundreds of homes on Kauai and Oahu were completely destroyed by Iwa's fierce winds.

Hundreds of homes on Kauai and Oahu were completely destroyed by Iwa’s fierce winds. The storm’s winds had an unusually high gust ratio, meaning wind gusts were higher than would be expected considering the storm’s official intensity.

At left, the bottom level of a complex in Poipu was gutted by Hurricane Iwa's storm surge. At right, a destroyed building at Schofield Barracks on Oahu ().

At left, the bottom level of a beachfront complex in Poipu was gutted by Hurricane Iwa’s storm surge. At right, destroyed buildings at Schofield Barracks on Oahu, where winds were funneled down the Wai’anae Range. (Image by Y. Ishii)

September, 1992 – Hurricane Iniki

Hurricane Iniki was by far the most intense tropical cyclone to affect Hawaii in recorded history.

Hurricane Iniki was by far the most intense tropical cyclone to affect Hawaii since the turn of the 20th century.

□ During the unusually active 1992 Central Pacific Hurricane season, Tropical Storm Iniki developed far southeast of Hawaii in the Intertropical Convergence Zone. The Central Pacific Hurricane Center initially did not consider the storm a threat as it slowly organized and travelled due west through unusually favorable atmospheric conditions. On September 9th, Iniki attained hurricane status 450 miles southeast of the Big Island (CPHC, 2013). While most tropical cyclones remain well south of the islands, an unseasonal low pressure system in the Northwest Pacific caused Hurricane Iniki to slow down almost due south of Oahu. During the overnight hours of September 10th, the storm made an abrupt turn to the north and began accelerating towards the western islands. Hurricane Iniki reached an intensity maxima approximately 130 miles south of Kauai on the morning of September 11th. A reconnaissance flight found sustained surface winds of 145mph and a central pressure of 938mb, making Hurricane Iniki a powerful category 4 hurricane and the most intense storm ever documented in the Central Pacific at the time (CPHC, 2013).

Hurricane Iniki made landfall in the early afternoon, allowing dozens of videographers to document the storm. At right, footage of a large surge-driven wave inundating a resort in Poipu.

Hurricane Iniki made landfall in the early afternoon, allowing dozens of videographers to document the storm. At left, wind gusts in excess of 130mph ravage Lihue (Image by Bruce Asato). At right, footage of a large surge-driven wave inundating a resort in Poipu.

Iniki entered a gradual weakening trend around 10am but maintained category 4 status as it sped northward at 25mph. At 3:30pm, Hurricane Iniki’s eye came ashore and traversed the western half of the island, leaving most of Kauai’s population within the dangerous right hemisphere of the storm. The exact intensity of Hurricane Iniki’s winds at landfall is unclear, but estimates range between 130 and 145mph. Considering the storm’s terrestrial pressure of 945mb, rapid forward pace and impressive satellite presentation, it is likely some portions of the island experienced category 4-force winds. An anemometer at Lihue Airport “pegged” at the instrument’s top value of 117mph in both the front and back eyewall of the hurricane, leading researchers to estimate a peak gust of 129mph (NOAA, 1993). The highest official wind gust recorded on Kauai was 143mph at Point Makahuena, but gusts over 160mph were estimated across the island. Vegetation was stripped bare on the slopes of Mount Waialaealae, indicating winds may have topped 200mph in certain mountainous locations. On Oahu, winds were generally moderate, but gusts of 82mph reportedly affected the Waianae coast (Survey Report, 1993).

At left, extreme wind and storm surge damage near Poipu. At right, a severely damaged oceanfront complex on Kauai. The debris line behind the building reveals the high water mark.

At left, extreme wind and storm surge damage near Poipu (Image by Nick Galante). At right, a severely damaged oceanfront complex on Kauai. The high water mark is visible behind the building (Image by Reed Saxon). Due to steep underwater topography, storm surge heights tend to be lower in Hawaii than other areas in the United States. The deep waters offshore do little to diminish swell energy, however, leading to large coastal waves.

Hurricane Iniki caused storm surge heights of up to six-feet on Kauai’s southern coast. Breaking waves over 35ft, however, led to high water marks over 22ft above sea level (Survey Report, 1993). On Oahu, a high water mark of 19ft was recorded at Makaha Shores, but most of the island encountered storm tides under four-feet. The remainder of the state was battered by giant surf, damaging or destroying hundreds of boats sheltering in normally calm southwest-facing harbors.

In total, Hurricane Iniki caused five direct fatalities – one man was killed by flying debris, one woman was crushed by a collapsing home and three people drowned in boats off Kauai (Survey Report, 1993). The monetary scope of the damage, amounting to approximately $3.5 billion (adjusted for inflation), was unprecedented in Hawaiian history. On Kauai, 1,421 homes were destroyed, primarily due to high winds, and the remainder of the island’s buildings were damaged to some degree (CPHC, 2013). The storm remains the most intense tropical cyclone to impact the Hawaiian Islands and proof that major hurricanes are capable of striking anywhere in the tropics of the Central Pacific.

Hurricane Iniki caused some of the most severe wind damage ever photographed in the United States. At left, severe damage to buildings in central Lihue (Image by Brian Howell). At right, dozens of industrial buildings were leveled or left as piles of twisted metal.

Hurricane Iniki caused some of the most severe wind damage ever photographed in the United States. At left, severe damage to buildings in central Lihue (Image by Brian Howell). At right, industrial buildings were reduced to piles of twisted metal.

A Detailed Look at the Category 5 Winds of Cyclone Tracy

Cyclone Tracy devastated the city of Darwin on Christmas Day, 1974. The storm caused more wind-related fatalities than any other tropical cyclone in a developed nation since 1950 and nearly led to the abandonment of half the city.

□ The city of Darwin, which sits alone atop Australia’s northern coastline, experienced a large surge of development in the years following World War II. Despite the existence of fairly standard building regulations, much of the city and its suburbs were constructed quickly in the 50’s and 60’s, causing many developers to turn a blind eye to the structural codes (Risk Assessment Model). As the city had not experienced a severe cyclone in many decades, the new suburban neighborhoods were built primarily with the tropical heat in mind. To take advantage of afternoon breezes, homes were elevated atop cement pillars and fitted with louvres for ventilation. By 1970, more than 40,000 people called the growing city home.

On December 22nd, 1974, a swirling mass of rain entered within range of the Darwin radar. The storm, named Cyclone Tracy the previous evening, appeared small and meek as it spun ever so slowly to the southwest. False alarms were commonplace in the tropics, and few paid much attention to radio warnings as the cyclone changed direction and slowly moved into the Beagle Gulf. Cyclone Tracy was an exceptionally small storm, being able to fit entirely within the 40 mile wedge between Bathurst Island and mainland Australia.

Composite radar view of Cyclone Tracy on the evening of December 24th, with the city of Darwin highlighted in yellow. The eyewall surrounding the storm is unusually compact and symmetrical. Despite the center of the storm being a mere 15 miles from Darwin, the city was experiencing only moderate rain and breezy conditions. The most intense winds in the cyclone extended only a few miles beyond the edge of the eye.

Cyclone alerts warned that “very destructive winds” of 75mph (120 km/h) with gusts to 94mph (150 km/h) were expected to hit the area late Christmas Eve. Many residents boarded up their windows while some chose to wait-and-see with the impending storm, which was forecast to be of only moderate intensity – the equivalent of a minimal Category 1 hurricane in the Atlantic.

Only a dozen miles offshore, the eye of Cyclone Tracy contracted to less than seven miles in width. The storm would become the smallest tropical cyclone in history, with winds over 38mph (60 km/h) extending only 30 miles from the center of the storm, and hurricane force winds extending less than eight miles.* Unbeknownst to meteorologists at the time, the storm had significantly stronger winds than originally estimated, and was gaining intensity as darkness fell over Darwin the night of Christmas Eve.

*Tropical Storm Marco in 2008 became the smallest tropical cyclone in history, with gale force winds extending only 10 miles from its center. The storm was significantly weaker, however. No storm of greater intensity has ever approached the tiny diameter of Cyclone Tracy..

Obliterated homes in Darwin’s northern suburbs.

The Storm

Winds picked up across Darwin shortly after 11pm as a few brave holiday partygoers left city pubs and headed home. By 12am Christmas morning, gusts of 50mph (80km/h) were being recorded at the Darwin Airport, and the winds were increasing with each passing minute. Around 1am, serious damage began to occur as hurricane force gusts reached the coastline.

Convection surrounding Tracy’s pinpoint eye intensified throughout the night, causing the storm’s central pressure to drop to 950mb, or perhaps a bit lower. Later analysis concluded that Cyclone Tracy entered a period of “explosive deepening” in the hours prior to making landfall, causing the storm’s eye to contract to only 5 miles in width (Sydney Morning Herald, 1975). The cyclone’s extremely slow forward pace, under 5mph, meant that sections of Darwin were to experience hurricane force winds for more than three hours.

Wind trace from the Darwin Airport, located three miles inland and near the center of the storm’s path. Winds rapidly increased after 2:30am as the powerful eyewall came shore. A peak gust of 135mph (217 km/h) was recorded just before the anemometer failed at 3:10am. The failure likely coincided with the commencement of the storm’s highest winds, which likely intensified before the calm of the eye reached the area 40 minutes later. A false reading was created at the end of the trace as the instrument failed. (Mason and Haynes)

Severe damage at the RAAF base in Darwin. An Indonesian DC3 airplane, which had been anchored to multiple 44-gallon drums filled with concrete, was lifted and thrown completely over a nearby hangar (visible above). Many of the destroyed aircraft were later placed in the Darwin Air Museum as a memento to the cyclone. (RAAF)

Around 3am, homes near the coast began to experience the full force of Cyclone Tracy. Darwin residents, initially concerned with the damage to their homes, soon realized their lives were in danger. Just north of downtown, priest Ted Collins made a brief audio recording of the storm as it roared like a jet engine over town (best heard with headphones on high volume). Flying debris from thousands of disintegrating homes filled the air, puncturing boarded windows and banging loudly against the sides of homes. Terrified residents huddled in their bathrooms as their homes shook violently amidst the thundering winds. Slightly south of the worst conditions, a survivor from Fannie Bay described her experience:

One of the living room windows went. And, shortly thereafter, the louvers burst in the bedrooms. Next, I saw the hatch to the attic pop up, so I knew the roof was going. You could hear the tin being torn from the roof by the fierce wind…By this time the water was pouring through the windows and we were lying cold and wet. I could feel the movement of the floor under me and the shuttering of the house. (Gil Jennex)

Farther north, 17-year old Amanda White (nee Mills) was weathering the storm at her father’s home in Rapid Creek:

At one point the winds were so loud that it didn’t seem they could get any stronger. I could hear the roof being torn off, and then something large smashed through the bedroom wall and took some of the house along with it. Before I could get a good grip on the counter, the whole structure came apart. My arm was badly crushed from a piece of timber. All I felt I could do was pray that I wouldn’t feel any pain, if it took me or not.

Final view of Cyclone Tracy, around 5am, before the radar failed. The storm’s eye contracted to only 5 miles in width in the hours before landfall (Mason and Haynes, 2010). As the leading edge of the back eyewall began impacting the airport, the radar failed, effectively ending all local analysis of the storm.

Extreme wind damage in Casuarina, one of Darwin’s northern suburbs. Entire forests were stripped of leaves and branches by the storm, an indication of extreme intensity. (Image by Rick Stevens)

The eye provided a brief 40 minute respite, confusing many into thinking the storm had passed. Survivors described the back eyewall of the storm as even more fierce than the front, accompanied by a roar that was heard several minutes before the winds recommenced. Due to the storm’s slow speed, the severe nature of the “second wind” was unusual. Some researchers later concluded that the winds in the western eyewall may have appeared more intense due to the multitude of debris left behind by the first half of the storm. Others researchers believe the storm continued to intensify slightly after landfall. One study also concluded that “decreased fetch roughness” in the back eyewall may have led to their increased intensity in the northern suburbs (Mason and Haynes).

By daylight on Christmas Day, 71 people had been killed directly by the storm. Most of the 50 fatalities that occurred on land were in the northern suburbs, where the most extreme damage occurred. A detailed report on 46 of the fatalities concluded that 33 of the victims were crushed by collapsed buildings, and another 13 deaths were related to flying debris, mostly from slicing pieces of metal but also from “penetration” by flying timber. Injuries sustained from being blown out of elevated houses was also a contributing factor in some of the deaths (Mason and Haynes). In one instance, an injured man sought shelter in a neighbor’s home during the eye of the cyclone, only to be killed when the house was leveled in the second half of the storm.

Cyclone Tracy caused more wind related fatalities than any other tropical cyclone to impact the United States or Australia since the turn of the 20th century. Hurricane Andrew, which struck a more populated area as a Category 5 hurricane in 1992, caused only 14 wind-related deaths. The high number of victims is likely the result of four factors – the extreme intensity of the winds, the duration of the slow-moving cyclone, the building construction in the area and the lack of evacuation preceding the storm (Griffith Review).

Image of trees that were stripped of leaves and branches by Cyclone Tracy. Such damage is generally only seen in powerful tropical cyclones with wind gusts exceeding 150mph. (Northern Territory Library)

A bus at the RAAF base was flipped multiple times and crushed by Cyclone Tracy (RAAF).

Debate still exists over the exact strength of Tracy’s winds. Observations at the Darwin Airport indicated that sustained winds were rapidly intensifying when the instrument failed at 3:10am. According to the on-hand weather observers, the calm center reached the airport at 3:50am, so the 40 minutes preceding the eye, as well as the back eyewall of the cyclone, were not recorded. Therefore, it is probable that wind gusts significantly higher than 135mph affected the airport, which was south of the worst affected areas.

Another notable variable is the pressure gradient of the cyclone. Observations in northern Darwin indicate that Tracy had a pressure gradient of 5.5mb per kilometer, or 8.8mb per mile (Courtney and Knaff, 2008). Such a steep gradient is comparable to some of the most intense Category 5 hurricanes in the Atlantic. While the central pressure of the storm was likely somewhere between 946 and 950mb, typical of a strong Category 3 hurricane in the Atlantic, the storm’s small size compressed the pressure difference into an unusually small area.

At left, an apartment building that lost its upper floor. At right, a devastated home in Rapid Creek.

The official report following the cyclone estimated peak gusts reached 150mph, or 240 km/h (Bureau of Meteorology Report). A more recent study suggests that maximum gusts were more likely around 162mph, or 260 km/h (Mason and Haynes). Some unofficial estimates place the highest gusts at 185mph (300 km/h) (Sydney Morning Herald, 1975). Considering the severity of the damage, including dozens of flipped vehicles and the deformation of thick steel beams, it is probable that many locations experienced gusts greater than 160mph.

A number of meteorologists have suggested that vortices imbedded in the storm’s eyewall (later identified as “miniswirls” following Hurricane Andrew in 1992) may have been responsible for some of the more extreme damage. Evidence pointing to the existence of violent, small-scale wind features included a refrigerator that was found imbedded in the side of a water tower 50ft above the ground (Sydney Morning Herald, 1975). Pilots in the area also sighted tornadic vortices within the storm.

Cyclone Tracy officially remains a Category 4 on the Australian Cyclone Scale, with sustained winds between 100mph and 123mph. The damage caused by the storm, however, suggests that the cyclone was significantly more intense.

Vehicles flipped by Cyclone Tracy. The car at distance appears to have been tossed from a parking stall, perhaps as far as 20ft. There does not appear to be any nearby wall which could have provided upward lift, as is commonly the case when cars are moved by hurricanes. A recent study that placed vehicles in wind tunnels concluded that winds of 150 to 180mph were required to overturn minivans at less “sensitive” angles (Lyons, 2009).

A car was blown into the pool of the Darwin Travelodge in downtown.

Extreme damage from Cyclone Tracy. At far right, a large steel electricity pole that was twisted and snapped by the storm’s violent winds. Cyclone Tracy remains the most damaging weather event in Australian history, and one of the most violent windstorms ever documented.