Cyclone Waka
Severe Tropical Cyclone Waka (Fiji Meteorological Service designation: 03F, Joint Typhoon Warning Center designation: 07P) was one of the most destructive tropical cyclones ever to affect the South Pacific Kingdom of Tonga. Waka originated within the near-equatorial trough in mid-December 2001, although the system remained disorganized for more than a week. The storm gradually matured and attained tropical cyclone status on December 29. Subsequently, Waka underwent rapid intensification in which it attained its peak intensity as a Category 4 severe tropical cyclone (Australian tropical cyclone intensity scale) on December 31, with winds of 185 km/h  (115 mph). Shortly thereafter, it passed directly over Vavaʻu, Tonga, resulting in widespread damage. By January 1, 2002, the cyclone began to weaken as it underwent an extratropical transition. The remnants of Waka persisted for several more days and were last observed near the Southern Ocean on January 6, 2002. Although the storm affected several countries along its path, Waka left the most significant losses in Tonga, where it killed one person and wrought 104.2 million paʻanga ($51.3 million USD) in damage. Hundreds of structures, including 200 in the island's largest city, and much of the nation's  agriculture were destroyed. Winds in excess of 185 km/h (115 mph) battered Vava'u, defoliating nearly every tree on the island. In addition to infrastructural and public losses, the environment was also severely affected; a native species of bat lost roughly 80% of its population due to the lack of fruit. Following the storm, Tonga requested international aid to cope with the scale of damage. Due to the severity of damage, the name Waka was later retired and replaced with Wiki. According to a study by Janet Franklin et al., storms similar in intensity to Waka, on average, strike Tonga  once every 33 years. Meteorological history. In mid-December 2001, at the end of a Madden–Julian oscillation pulse, twin equatorial monsoonal troughs developed in the Northern and Southern Hemispheres. Although warm sea surface temperatures of in the region favored development of a tropical cyclone, the southern trough developed substantially slower than the northern one. On December 19, the southern component was classified as Tropical Depression 03F by the Fiji Meteorological Service; at this time the depression was situated just east of the Solomon Islands. The northern component eventually developed into Typhoon Faxai, an extremely powerful Category 5 equivalent cyclone . Unlike Faxai, the precursor to Cyclone Waka developed slowly, mainly because of moderate wind shear in the region. Moving southeastward, the system gradually became more organized. On two occasions, the Joint Typhoon Warning Center (JTWC) issued a Tropical Cyclone Formation Alert; however, the agency later canceled them both times. By December 27, the depression had entered a region of lesser shear, favoring significant development of the system. The following day, the JTWC classified the system as Tropical Depression 07P, when the storm was situated roughly northwest of Pago Pago, American Samoa. Tracking towards the southwest in response to a mid -level ridge to the southeast, the depression quickly intensified, attaining gale-force winds on December 29. Upon doing so, it was upgraded to a tropical cyclone and given the name Waka. Shortly thereafter, the storm underwent rapid intensification; roughly 24 hours after being named, Waka attained sustained winds of 120 km/h (75 mph). During December 30, the center of the storm brushed Wallis Island before turning towards the southeast and accelerating due to an approaching trough from the northwest. Continuing to intensify, Waka passed directly over Niuafo'ou on December 31 with winds of 150 km/h (90 mph). Later  that day, the cyclone attained its peak intensity as a Category 4 severe tropical cyclone with ten-minute sustained winds of 185 km/h (115 km/h) and a barometric pressure of 930 mbar (hPa; ). The JTWC assessed the storm to have attained similar one-minute sustained winds upon peaking; however, this was due to discrepancies between the two warning centers. At this time, Waka displayed a well-defined, circular eye roughly in diameter. Shortly after attaining its peak intensity, the center of Waka passed over Vava'u. Continuing into the new year, Waka gradually weakened on January 1, 2002 as  it entered a less favorable region for tropical cyclones. As a result, wind shear displaced convection from the center and its eyewall broke apart. Moving over decreasing sea surface temperatures, Waka began to undergo an extratropical transition, which it completed on January 2. Tracking southeastward, the remnant cyclone briefly slowed over open waters before again accelerating. Over the following few days, the system gradually weakened, with sustained winds decreasing below gale-force by January 5. The storm was last noted on January 6 near the Southern Ocean, about north-northwest of Antarctica, at which time it had a pressure of  972 mbar (hPa; 28.7 inHg). Preparations and impact. Tonga. On December 30, just a day before Waka passed through Tonga, warnings were issued for numerous islands, including parts of Fiji and Samoa. Forecasts showed the storm passing directly over the low-lying Tongan capital of Nuku'alofa as a Category 3 cyclone. Owing to warnings from local media, all New Year's Eve celebrations were canceled as residents and tourists boarded up their homes. All airports in the region were shut down and ferry service was suspended. Many residents on the small island of Niuafo'ou, about 35 km (13.5 mi) in  size, evacuated to other islands prior to Waka's arrival. When the storm was moving through the islands of Tonga at peak strength, a few islands recorded hurricane-force winds; the city of Neiafu measured the strongest winds, peaking at 185 km/h (115 mph). In the southern islands, wind gusts up to 250 km/h (155 mph) affected isolated areas. In the Haʻapai islands, sustained winds reached 100 km/h (65 mph) and gusted to 140 km/h (85 mph). Heavy rains also fell during Waka's passage, amounting to over in Haʻapai. Initial reports from Nukuʻalofa on December  31 indicated severe agricultural damage but few infrastructural losses. Following the passage of Waka, communication with Niuas and Vava'u were lost. According to local reports, high winds sandblasted Neiafu and downed nearly every tree. Surveys by the Red Cross revealed that roughly 200 homes in the city were severely damaged or destroyed and those left standing lost their roofs. Vava'u lost roughly 90% of its crops, including essential food crops such as taro, yams and bananas. In Ha'apai, one person died from cardiac arrest brought on by the storm. Fallen trees blocked numerous roads; power and water supplies were also  interrupted to most residents. Severe damage also took place on Niuatoputapu where coastal homes were impacted by Waka's storm surge and several structures lost their roofs. In one instance, a yacht was brought onshore by the surge and crashed into a restaurant, destroying both. According to damage surveys, 13 of the country's islands sustained damage; 470 homes and 6 schools were destroyed and hundreds more damaged. Damage throughout Tonga amounted to 104.2 million paʻanga ($51.3 million USD). In addition to infrastructural and public damage, the environment sustained catastrophic losses on Tonga. The Insular Flying Fox ("Pteropus tonganus