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Severe Tropical Cyclone Hina in March 1997 was the worst tropical cyclone to affect the South Pacific island nation of Tonga since Cyclone Isaac in 1982. The system was first noted within the monsoon trough on March 11, 1997, as a weak shallow depression within the vicinity of Rotuma. Over the next two days, the depression remained near Rotuma with no preferred movement, as it started to develop further within favorable conditions for further development. The system was subsequently named Hina on March 15, after it had started to move eastwards and had passed to the southeast of Niulakita, Tuvalu. During that day the system moved south-eastwards and impacted Wallis and Futuna, before it passed over Tonga's southern islands of Tongatapu and 'Eua during March 16. After impacting Tonga the system moved rapidly towards the south-southeast and weakened below tropical cyclone intensity, before it was last noted on March 21 about to the south of the Pitcairn Islands. During the systems post analysis it was determined that the warning centers had underestimated Hina's intensity as it passed over Tonga, after damage had been greater than expected in the island nation. Within Tuvalu it was difficult to assess damage done by Hina alone, after Cyclone Gavin impacted the area a week earlier. Storm surge and strong winds from both cyclones caused a severe amount of coastal erosion on all of the country’s nine atolls, with about 6.7% of land washed into the sea. Hina caused no significant damage on Walls Island, while it caused some damage to crops and destroyed parts of the road on Futuna Island. As Hina affected Tonga, there were no casualties reported as the system affected the island nation, however, Vaiola Hospital reported that they had treated a number of patients for injuries that were caused during the systems aftermath. One indirect death was also reported, after a person suffering a heart attack while evacuating from his home. The cyclone left extensive damage to utilities and agriculture on Tongatapu, where trees were uprooted and more than of fruit and food crops were destroyed, mostly to banana and coconut trees. After the cyclone the Tongan Government requested and received emergency aid, from the governments of several countries including France, Australia, New Zealand, Japan and the United Kingdom. This was after the government had provided T$5 million (US$3.97 million), or about 5% of its national budget to facilitate the immediate start of emergency relief and repairs to essential services. ==Meteorological history== On March 11, 1997, the Fiji Meteorological Service's Regional Specialized Meteorological Center in Nadi, Fiji (RSMC Nadi) started to monitor a shallow tropical depression, that had developed along the monsoon trough near the Fijian Dependency: Rotuma. Over the next two days the depression remained near Rotuma with no preferred movement, as it started to develop further in an area of minimal vertical wind shear and good upper air divergence.〔 Early on March 13, as the system moved northwards, RSMC Nadi relocated the depression to about to the northwest of Rotuma. Later that day, the United States Joint Typhoon Warning Center (JTWC) subsequently initiated advisories on the system and designated it as Tropical Cyclone 33P, after it had become equivalent to a tropical storm with 1-minute sustained winds of . after having moved to the north, Hina curved to the east and southeast During that day after having moved to the north, Hina curved to the east and later south-eastwards, before it passed about to the southeast of Niulakita the southernmost island of Tuvalu during March 14.〔 Early on March 15, after the system had passed near Niulakita, RSMC Nadi reported that the depression had developed into a category 1 tropical cyclone on the Australian tropical cyclone intensity scale and named it Hina.〔 After being named the system accelerated towards the south-southeast and an area of increasing vertical wind shear as it passed near the west coast of Futuna Island.〔 The system also crossed the 180th meridian during that day, which prompted the JTWC to pass the responsibility for warning the United States Government to the Naval Pacific Meteorology and Oceanography Center (NPMOC). Early on March 16, as Hina passed over the southern islands of Tonga, RSMC Nadi reported that based on satellite imagery and guidance from other meteorological centers, the system had 10-minute sustained wind speeds of .〔 Hina subsequently passed over the islands of Tongatapu and ʻEua in southern Tonga at around 08:30 UTC and took less than 2 hours to inflict considerable damage on the islands.〔 The system subsequently emerged back into the South Pacific Ocean, with RSMC Nadi estimating that the system had storm force winds of about . Later that day the NPMOC estimated that Hina had peak 1-minute sustained windspeeds of as it rapidly moved below 25°S and out of RSMC Nadi's area of responsibility.〔 Over the next few days the system continued to move towards the south-southeast and gradually weakened, before the NPMOC issued its final advisory during March 18, as the system was undergoing a transition to become an extratropical cyclone. The system weakened below tropical cyclone intensity during the next day, before it was last noted by the Wellington Tropical Cyclone Warning Center on March 21, while located about to the south of the Pitcairn Islands.〔 After an analysis of the observed data and the damage in Tonga, RSMC Nadi assessed that Hina's landfall intensity was underestimated.〔 The observed wind data suggested that the system had storm force sustained winds but had peak gusts comparable to hurricane force.〔 Furthermore, the lowest pressure values also indicated that the winds had to be stronger than estimated for it to fit known wind pressure relationships.〔 It was subsequently deduced by RSMC Nadi that Hina was a minimal category 3 severe tropical cyclone, with peak 10-minute sustained wind speeds of when it crossed the Tonga island of Tongatapu at around 08:30 UTC (21:30 UTC+13).〔 The NPMOC also revised their estimate of Hina's peak 1-minute sustained wind speeds from to during post analysis, which made the system equivalent to a category one hurricane on the Saffir–Simpson hurricane wind scale.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Cyclone Hina」の詳細全文を読む スポンサード リンク
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