Severe Tropical Cyclone Ula was a powerful and long-lived

tropical cyclone A tropical cyclone is a rapidly rotating storm system characterized by a low-pressure center, a closed low-level atmospheric circulation, strong winds, and a spiral arrangement of thunderstorms that produce heavy rain and squalls. Dep ...

during late December 2015 and mid-January 2016. It originated from a tropical disturbance on December 26, 2015, east of the

Solomon Islands Solomon Islands is an island country consisting of six major islands and over 900 smaller islands in Oceania, to the east of Papua New Guinea and north-west of Vanuatu. It has a land area of , and a population of approx. 700,000. Its ca ...

. Moving generally east, development was initially slow and the system finally reached cyclone strength—having

gale A gale is a strong wind; the word is typically used as a descriptor in nautical contexts. The U.S. National Weather Service defines a gale as sustained surface winds moving at a speed of between 34 and 47 knots (, or ).rapidly intensified In meteorology, rapid intensification is a situation where a tropical cyclone intensifies dramatically in a short period of time. The United States National Hurricane Center defines rapid intensification as an increase in the maximum sustained wi ...

, attaining hurricane-strength the following day. A shift to the southwest brought the system close to the northern islands of

Tonga Tonga (, ; ), officially the Kingdom of Tonga ( to, Puleʻanga Fakatuʻi ʻo Tonga), is a Polynesian country and archipelago. The country has 171 islands – of which 45 are inhabited. Its total surface area is about , scattered over in ...

on January 2, 2016. It subsequently brushed several islands in the Lau Group of Fiji before weakening. Nearly degrading to a tropical depression, Ula turned to the northwest and regained strength. After turning back to the southwest, it achieved its peak intensity as a Category 4 on the Australian scale with winds of 185 km/h (115 mph) on January 10. Thereafter, the storm bypassed

Vanuatu Vanuatu ( or ; ), officially the Republic of Vanuatu (french: link=no, République de Vanuatu; bi, Ripablik blong Vanuatu), is an island country located in the South Pacific Ocean. The archipelago, which is of volcanic origin, is east of no ...

to the southeast and New Caledonia to the east as it accelerated southward. Throughout its existence, Ula affected several nations but its effects were largely limited, with only localized areas reporting damage. Dozens of structures were damaged or destroyed in

Tuvalu Tuvalu ( or ; formerly known as the Ellice Islands) is an island country and microstate in the Polynesian subregion of Oceania in the Pacific Ocean. Its islands are situated about midway between Hawaii and Australia. They lie east-northea ...

while crops in Tonga, Fiji, and Vanuatu were impacted. No fatalities have been attributed to the storm, though one person was swept out to sea in American Samoa and was not found. Residents across the Lau Islands of Fiji required

food security Food security speaks to the availability of food in a country (or geography) and the ability of individuals within that country (geography) to access, afford, and source adequate foodstuffs. According to the United Nations' Committee on World F ...

due to crop losses.

Meteorological history

In late December 2015, a long-lived and powerful

westerly wind burst A westerly wind burst is a phenomenon commonly associated with El Niño events, whereby the typical east-to-west trade winds across the equatorial Pacific shift to west-to-east. A westerly wind burst is defined by Harrison and Vecchi (1997) as sust ...

triggered the formation of a tropical disturbance in the south Pacific, along with its twin in the central North Pacific, which became Tropical Depression Nine-C. On December 26, 2015,

Fiji Meteorological Service The Fiji Meteorological Service (FMS) is a Department of the government of Fiji responsible for providing weather forecasts and is based on the grounds of Nadi Airport in Nadi. The current director of Fiji Meteorological Service is Misaeli Funa ...

(FMS) began monitoring the poorly-organized tropical disturbance, dubbed ''05F'', to the east of the

. Tracking east, the system struggled to develop within a highly sheared environment. By December 29, the system was centered roughly 230 km (145 mi) northeast of

Pago Pago Pago Pago ( ; Samoan: )Harris, Ann G. and Esther Tuttle (2004). ''Geology of National Parks''. Kendall Hunt. Page 604. . is the territorial capital of American Samoa. It is in Maoputasi County on Tutuila, which is American Samoa's main island ...

American Samoa American Samoa ( sm, Amerika Sāmoa, ; also ' or ') is an unincorporated territory of the United States located in the South Pacific Ocean, southeast of the island country of Samoa. Its location is centered on . It is east of the Internation ...

, and had developed a low-level circulation accompanied by persistent

convection Convection is single or multiphase fluid flow that occurs spontaneously due to the combined effects of material property heterogeneity and body forces on a fluid, most commonly density and gravity (see buoyancy). When the cause of the c ...

. Development hastened throughout the day, with banding features forming and upper-level

outflow Outflow may refer to: * Capital outflow, the capital leaving a particular economy * Bipolar outflow, in astronomy, two continuous flows of gas from the poles of a star * Outflow (hydrology), the discharge of a lake or other reservoir system *Outflo ...

becoming established over the system. The system soon acquired

gale A gale is a strong wind; the word is typically used as a descriptor in nautical contexts. The U.S. National Weather Service defines a gale as sustained surface winds moving at a speed of between 34 and 47 knots (, or ).UTC. Ula moved to the south and eventually west as the system intensified. By January 2, Ula had attained hurricane strength as the storm was upgraded into a Category 2 Tropical Cyclone. Ula has subsequently attained a preliminary peak intensity at Category 3 tropical cyclone status, equivalent to Category 2 hurricane status. Ula weakened afterwards, only to re-intensify to category 3 status again the next day. By January 7, however, Ula turned northwest, slowed and dropped to tropical cyclone status. With the unfavorable conditions, Ula remained at that status for three days. On January 10, Ula rapidly re-intensified to a peak intensity of 115 mph (ten-minute sustained) or 140 mph (one-minute sustained) winds. This constituted as peak intensity and Ula was upgraded to category 4 severe tropical cyclone status, and the Joint Typhoon Warning Center upgraded Ula to a category 4 cyclone. Ula kept category 4 status for 24 hours before an abrupt weakening to a tropical depression. By 12:00 UTC on January 12, Ula transitioned into an extratropical cyclone.

Preparations and impact

Tuvalu and American Samoa

Early in the storm's existence, Ula produced winds up to across

, uprooting trees and leaving 40 homes and 10 businesses damaged, some beyond repair Thirty families required evacuation. Waves of also battered the islands, whose highest elevation is only . A fisherman went missing in

Faleasao Faleāsao is a village in American Samoa American Samoa ( sm, Amerika Sāmoa, ; also ' or ') is an unincorporated territory of the United States located in the South Pacific Ocean, southeast of the island country of Samoa. Its location is ...

, American Samoa, after being swept out to sea by large swells. After 72 hours, fruitless search efforts were called off.

Tonga

On January 1, Tongan

Prime Minister A prime minister, premier or chief of cabinet is the head of the cabinet and the leader of the ministers in the executive branch of government, often in a parliamentary or semi-presidential system. Under those systems, a prime minister is ...

ʻAkilisi Pōhiva Samiuela ʻAkilisi Pōhiva (7 April 1941 – 12 September 2019) was a Tongan pro-democracy activist and politician. Pohiva, the leader of the Democratic Party of the Friendly Islands (DPFI), served as the Prime Minister of Tonga from 2014 to h ...

preemptively declared a

state of emergency A state of emergency is a situation in which a government is empowered to be able to put through policies that it would normally not be permitted to do, for the safety and protection of its citizens. A government can declare such a state du ...

for the

Vavaʻu Vavau is an island group, consisting of one large island ( ʻUtu Vavaʻu) and 40 smaller ones, in Tonga. It is part of Vavaʻu District, which includes several other individual islands. According to tradition, the Maui god created both Tongatap ...

and

Haʻapai Haʻapai is a group of islands, islets, reefs, and shoals in the central part of Tonga. It has a combined land area of . The Tongatapu island group lies to its south, and the Vavaʻu group lies to its north. Seventeen of the Haʻapai islands are ...

islands. Eleven shelters were opened, with 390 seeking refuge in them. Flights across the nation were suspended for the duration of the storm. Strong winds up to downed trees, power lines, and tore roofs from homes, with Vava'u suffering the brunt of the damage. Overall damage was limited, however, and the previously issued state of emergency was lifted on January 6.

Fiji

After brushing Tonga, Fiji's

Lau Islands The Lau Islands aka little Tonga (also called the Lau Group, the Eastern Group, the Eastern Archipelago) of Fiji are situated in the southern Pacific Ocean, just east of the Koro Sea. Of this chain of about sixty islands and islets, about thirty ...

were in the path of Ula. Officials across the small islands advised residents to move to higher ground and seek shelter in sturdy buildings. Boat services across the

Yasawa Islands The Yasawa Group is an archipelago of about 20 volcanic islands in the Western Division of Fiji, with an approximate total area of . Geography The Yasawa volcanic group consists of six main islands and numerous smaller islets. The archi ...

were temporarily suspended. Though the cyclone passed close to a few islands, damage was relatively limited. Corrugated iron roofs were blown off some structures on

Ono-i-Lau Ono-i-Lau is a group of islands within a barrier reef system in the Fijian archipelago of Lau Islands (''ono'' means "six" in the Fijian language Fijian (') is an Austronesian language of the Malayo-Polynesian family spoken by some 350,000� ...

and Kabara. Two homes were destroyed on

Vatoa Vatoa (pronounced ) (known as Turtle Island after Cook's visit) is an outlier of Fiji's Lau Group. History Vatoa was the only island of present-day Fiji visited by James Cook. The island was sighted on 2 July 1774. The next day, a Sunday, t ...

. Power and water supplies were temporarily disrupted. Crops also sustained significant damage, with 50 percent lost across the Lau Islands, prompting the Fijian Government to provide a month's-worth of food rations to residents across 13 villages. General relief supplies, including disaster kits, medicine, and water purifying tablets, were also distributed to Ono-i-Lau, Ogea,

Fulaga Fulaga (pronounced ) (proper name: Vulaga) is a crescent-shaped reef-limestone island An island or isle is a piece of subcontinental land completely surrounded by water. Very small islands such as emergent land features on atolls can be cal ...

and Kabara. The cyclone's outer bands caused flooding in northern provinces, including Ba. Rainfall was largely beneficial to the nation, particularly for the Western Division, which was in the midst of a

drought A drought is defined as drier than normal conditions.Douville, H., K. Raghavan, J. Renwick, R.P. Allan, P.A. Arias, M. Barlow, R. Cerezo-Mota, A. Cherchi, T.Y. Gan, J. Gergis, D. Jiang, A. Khan, W. Pokam Mba, D. Rosenfeld, J. Tierney, an ...

Vanuatu and New Caledonia

Vanuatu's southernmost province of

Tafea Tafea is the southernmost of the six provinces of Vanuatu. The name is an acronym for the five main islands that make up the province: Tanna, Aneityum, Futuna, Erromango and Aniwa. History Unlike the other provinces of Vanuatu, the territoria ...

was placed on alert in advance of Ula's approach. The province was devastated by

Cyclone Pam Severe Tropical Cyclone Pam was the second most intense tropical cyclone of the South Pacific Ocean in terms of sustained winds and is regarded as one of the worst natural disasters in the history of Vanuatu. A total of 15–16 people lost ...

in March 2015, but reported to be prepared to endure another storm. Residents were urged to evacuate and fishermen were advised to return to port. The storm ultimately remained far enough away to cause only limited damage, primarily to agriculture on

Aneityum Aneityum (also known as Anatom or Keamu) is the southernmost island of Vanuatu, in the province of Tafea. Geography Aneityum is the southernmost island of Vanuatu (not counting the Matthew and Hunter Islands, which are disputed with New Caledo ...

and Futuna islands. Alerts were temporarily raised for

Maré Island Maré Island or Nengone (french: Île de Maré) is the second-largest of the Loyalty Islands, in the archipelago of New Caledonia, an overseas territory of France in the Pacific Ocean. The island is part of the commune (municipality) of Maré ...

, New Caledonia; Ula eventually passed harmlessly to the east of the island.

Notes

References

External links

{{DEFAULTSORT:Ula (2016) 2015 in American Samoa 2015–16 South Pacific cyclone season 2015 in Tuvalu 2016 in Fiji 2016 in Vanuatu Category 4 South Pacific cyclones Tropical cyclones in American Samoa Tropical cyclones in Fiji Tropical cyclones in New Caledonia Tropical cyclones in Tuvalu Tropical cyclones in Vanuatu January 2016 events Retired South Pacific cyclones Ula Ula