Cyclone Namu

Map plotting the track and the intensity of the storm, according to the Saffir–Simpson scale

During the middle of May 1986, the monsoon trough of low pressure became very active, between the island nations of Tuvalu and the Solomon Islands.[3] Over the next couple of days, two depressions developed within this monsoon trough, with the first going on to become Typhoon Lola in the Northern Hemisphere.[4] The second depression developed within the Southern Hemisphere and was first noted by the Fiji Meteorological Service (FMS) during May 15, while it was located about 165 km (105 mi) to the north of Malaita in the Solomon Islands.[5] During the next day, as the depression moved eastwards, it showed signs of weakening with clouds associated with the system disintegrating.[3] However, the system remained in an area favourable for Tropical cyclogenesis, before the system re-intensified and developed two weak feeder bands.[3] The United States Joint Typhoon Warning Center (JTWC) subsequently started to issue warnings on the system and designated it as Tropical Cyclone 33P early on May 17, after the depression had developed gale-force winds.[6] During that day, the system moved south-westwards and acquired the characteristics of a tropical cyclone, before it was named Namu by the FMS, while it was located about 55 km (35 mi) to the north of Sikaiana.[7][8]

After being named, the system continued to move south-westwards and continued to intensify, before an eye feature was reported as it passed over Malaita during May 18.[5] After Namu had crossed Malaita, the FMS estimated that Namu had developed a small ring of hurricane-force winds, about 20–30 km (10–20 mi) from the centre.[3] They also estimated that the system had peaked with 10-minute sustained wind speeds of 150 km/h (90 mph), which made it a Category 3 severe tropical cyclone on the Australian tropical cyclone intensity scale.[9] At around this time, the JTWC estimated that Namu had peaked with 1-minute sustained wind speeds of 155 km/h (100 mph), which made it equivalent to a Category 2 hurricane on the Saffir-Simpson hurricane wind scale.[6][9] The system subsequently crossed Guadalcanal and 160°E where it moved into the Australian region during May 19, where a broad and ragged eye became visible in satellite imagery but quickly became obscured by high cloud.[3] Namu subsequently came under the influence of high level westerly winds, which steered the system on a south-easterly track and back into the South Pacific basin.[3] After it moved back into the South Pacific basin, Namu accelerated towards southern Vanuatu and rapidly weakened into a depression, as cold air from the subtropics wrapped into the system.[10] Namu subsequently dissipated during May 22, after it had become sheared in the middle levels and merged into an eastwards moving trough of low pressure near south-eastern Vanuatu.[3][4]

Bridge damaged by Namu

Severe Tropical Cyclone Namu impacted the Solomon Islands, Vanuatu and New Caledonia and caused over 100 deaths, as well as varying amounts of damage to the island nations.[7] As a result, the name Namu was later retired from the lists of tropical cyclone names for the South Pacific by the World Meteorological Organization.[11] Within the Solomon Islands, Namu was considered to be one of the biggest and worst natural disasters in the Solomon Islands on record, as it caused extensive damage and the deaths of over 100 people.[3][8]

Severe Tropical Cyclone Namu was considered to be one of the biggest and worst natural disasters in the Solomon Islands on record, as it caused extensive damage and the deaths of over 100 people.[3][8] As a result of its impact on the island nation, the name Namu was later retired from the lists of tropical cyclone names for the South Pacific by the World Meteorological Organization.[11] The system impacted the Solomon Islands between May 16 - 19, with hurricane force winds, high seas, storm surge, torrential and prolonged rainfall.[3]

The FMS started to issue special weather bulletins for the Solomon Islands Meteorological Service (SIMS) during May 15, which advised that the system had gale force winds associated with it and that it would affect Malaita and smaller islands.[3] As a result, the SIMS issued a gale warning before the bulletins were suspended during the next day, after the system weakened and it became doubtful that gales were associated with the depression.[3][8] After the depression was named Namu during May 17, the FMS resumed issuing the weather bulletins, which advised the SIMS of the threat posed by Namu to Malaita, Guadalcanal, San Cristobal and other smaller islands.[3] Over the next few days, these bulletins were revised accordingly and advised the SIMS which areas would be affected by gale, storm and hurricane-force winds and the threat of flooding from rain or storm surge.[3] These bulletins were subsequently used by the SIMS to prepare various gale and tropical cyclone warnings, which were subsequently broadcast in English and Pidgin around the clock by the Solomon Islands Broadcasting Corporation.[8][12] However, many people were caught off guard by the cyclone's sudden increase in winds and the prolonged heavy rain, especially in remote areas where weather forecasts were difficult to disseminate because of communication problems.[3]

The storm's slow motion allowed for prolonged periods of heavy rainfall, with Honiara International Airport measuring 340 mm (15 in) of rain over a three-day period.[3][13] Hurricane or storm force winds affected Malaita, Small Malaita, Guadalcanal, Bellona, and other smaller islands that the cyclone's center passed within 50 to 65 km (30 to 40 mi). Gale-force winds covered a wide area, extending as far north as the northern tip of Malaita and as far south as San Cristóbal. Gusts in some areas were estimated to be as high as 185 km/h (115 mph).[3] On the islands of Bellona and Rennel, strong winds resulted in devastation.[14] The storm was estimated to have caused a maximum wave height of 1.5 m (4.9 ft).[13]

Most of the damage caused by Cyclone Namu occurred due to river flooding.[13][15] The cyclone affected 48% of the Solomon's land area and 62% of its total population.[16] Even though there are few rivers in the Solomon Islands, the ones that do exist are shallow and flood easily.[17] Of all the islands, Malaita was the worst affected by the cyclone due to Namu's rough seas and strong winds.[5] Along the eastern coast of the island, damage was massive; entire villages were destroyed. Gardens were devastated and walking pathways were blocked.[18][19][20] On Sikiana Island, a small island with a few hundred residents, only one house was left standing.[21] In Babanakira, 5 people died.[22]

On the island of Guadalcanal, a single mudslide was responsible for killing 38 villagers.[23] Of the 43 people that lived in the small town of Valebaibai, only 5 survived, all of whom narrowly escaped.[24] Moreover, 14 dead bodies were found in the central and southern areas of Guadalcanal on May 21 when flood waters began to recede.[25]

Deep flood water covered 75% of the island's (Guadalcanal) coastal plain;[26] these waters cut off channels and destroyed coastal villages. Furthermore, the Lungga, Ngalimbiu, Mberande, and Nggurambusu rivers sustained the worst flood damage;[27] water depth in some of the aforementioned rivers reached 8 m (26 ft).[28] Many trees were brought down due to high winds.[27] Also, numerous plantations were destroyed across the island. However, little beach erosion occurred on the island.[27] Moreover, 22% of homes on the island were either damaged or destroyed.[5] One bridge was also destroyed on the island.[29] Offshore Honiara, the capital of the nation, two ships [one was 60 ft (20 m) long and the other was 120 ft (35 m) long] each sank during the storm.[30] Throughout the capital, several schools were destroyed. The two bridges that connected the city with the island of Guadalcanal were destroyed, thus leaving Honiara isolated.[31] Furthermore, about 5,000 homeless were left homeless across the city,[32] 2,000 of whom sought refuge in a local college due to the storm. Although no people were to have confirmed to have died in the city, five children were reported missing in one of the capital's suburbs, Ngalimera.[31]

In both Guadalacal and Malatia, extensive areas of irrigated rice crops were submerged under floodwaters and mud.[3] In some areas, nearly all homes were destroyed. Mudslides and logs destroyed roads, bridges, water pipes and drainage systems. Crops such as cocoa, copra, coffee, and rice were destroyed, resulting in thousands of dollars in damage.[17][24] Although there are no reports of storm surge throughout the islands, it is likely that coastal areas suffered damage from surge.[3] Additionally, communication between the outer and island of the Solomon group was completely destroyed.[33]

In all, approximately 90,000 people, one third of the country's population, were reportedly homeless.[15][34] The southern islands of the Solomon's chain were seriously affected by the passage of Namu, becoming the worst tropical cyclone to impact the area in five years.[15] Of the 25,000 "traditional" houses on the Solomon Island, 6,000 (26%) were destroyed. Overall, Cyclone Namu is "positively identified" to have killed 111, some reports suggest at least 150 people perished due to Namu.[5][35] Most of the fatalities were due to landslides and flooding. Property damaged totaled $25 million (1986 USD)[24] and the storm also caused US $100 million in economic losses in the Solomon Islands.[36] On May 18, Honiara's Central Hospital authorities decided to evacuate several patients, as the hospital was located on a coastal strip that was vulnerable to river flooding and seawater inundation.[35]

During May 19, the Government of the Solomon Islands declared a state of national disaster and decided that the emergency period would run until May 31.[8][37] As a result, the government started to ask bilateral donors including Australia, New Zealand and the United Nations for assistance.[37] However, before any foreign assistance could arrive in the Solomon Islands, residents started to try to help themselves by patching up water pipes with bamboo, string and rubber strips.[24] New Zealand subsequently donated an initial NZ$1 million, while the Australian High Commission subsequently donated an initial AU$1.2 million worth of relief supplies.[37] This included two C-130 Hercules cargo planes from the Royal Australian Air Force, a detachment party, relief supplies and two Iroquois helicopters.[35][37][38] These aircraft arrived during May 21, when Henderson Field Airport reopened for emergency operations, after flood waters had receded and the mud and debris had been removed.[35]

Within a week following the storm, access to fresh water was resorted to the archipelago; doctors believed that had these services not been restored, widespread disease would have been reported.[39] The government declared June 2 a national day of mourning for the victims of the storm.[40]

The International Monetary Fund loaned $1.3 million USD to the nation.[41] Australian relief planes had dropped food to 4,000 victims in the highlands on the main island of Guadalcanal and New Zealand provided nearly 30,000 lb (13,610 kg) of rice, canned meat and tea to the devastated region. New Zealand engineers were brought in to assess damage to roads and bridges and start removal of 40 ft (10 m) high debris along the waterfronts of the island chain.[21] Also, $10,000 ECU was donated to the devastated island group.[42] Other countries, including the United Kingdom, Papua New Guinea, the United States, and Japan also sent supplies and goods to the Solomon Islands.[15] Overall, US$8.6 million was provided to the Solomons [43] and 71,000 lb (32,205 kg) worth of supplies were provided to victims of the cyclone.[44]

During May 26, Henderson Field was reopened for commercial flights

Moreover, a commercial aircraft provided supplies to the 200 inhabitants of Sikiana Island, which had run out of food a week after the storm.[45] In all, a total of 17 coastal trading vessels, four helicopters, and six aircraft were used to transport food, tents and medical supplies to the needy.[46] It was estimated that the homeless would require aid such as food for six months.[47]

Elsewhere, in Honiara, the local ministry asked each resident to pay $50 so that the roofs that were damaged by the system could be repaired.[48] The cleanup process took a long time; a year after the storm, bulldozers were reportedly still removing broken logs and not all roads had been repaired.[24] Following the storm, disease spread to isolated part of the Solomon Island group; many animals died and hundreds of children were hospitalized because of the outbreak of disease.[49]

On June 4, the Government of the Solomon Islands lifted the emergency period, four weeks after the system had impacted the islands.[35] After the emergency period was lifted, outside assistance that had been brought in to assist with relief efforts were gradually withdrawn, including armed services from Australia and New Zealand.[35] However, external assistance from Australia and New Zealand amongst others, was still needed due to the Solomon Islands reliance on overseas aid in general.[35] As a result, a two-day meeting took place in Honiara during July, at which the Solomon Islands Government requested and was promised about 13.5 million for 20 rehabilitation programs.[50] Pledges of assistance were made by Australia, Britain, New Zealand, the European Economic Community and agencies of the United Nations and the United States of America.[50] These programs included projects to replace rural primary schools flattened by the cyclone, bridges and water supply systems swept away by Namu.[50]

During March 1987, volunteers from the Australian Rotarians, commenced an eighteen-month project to build 93 schools in the Solomon Islands.[51][52]

Questions were raised during the systems aftermath over whether or not excessive deforestation worsened the impact of the flood. The government denied reports that deforestation had any link to the catastrophe.[53]

As a result of its impact on the Solomon Islands, the name Namu was later retired from the lists of tropical cyclone names for the South Pacific by the World Meteorological Organization.[11]

• Cyclone Uma - devastated a similar island group the following year
• List of off-season South Pacific tropical cyclones
• List of wettest tropical cyclones

• World Meteorological Organization
• Australian Bureau of Meteorology
• Fiji Meteorological Service
• New Zealand MetService
• Joint Typhoon Warning Center
• Devastation by cyclone - ABC News
• Impacts of a cyclone: days or decades? - ABC News