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Hurricane Hilda was the most intense tropical cyclone of the 1964 Atlantic hurricane season and ravaged areas of the United States Gulf Coast, particularly Louisiana. In addition to causing impacts inland, the hurricane greatly disrupted offshore oil production, and at its time was the costliest tropical cyclone for Louisiana's offshore oil production. Due in part to flights made by the National Hurricane Research Laboratory, Hilda became one of the most well-documented storms meteorologically in the Atlantic.〔 Lasting for seven days as a tropical cyclone, Hilda caused US$126 million in damage and 38 deaths. Hilda developed over the southern shores of Cuba on September 28 as a tropical depression, tracking westward in an area of favorable conditions and reaching tropical storm intensity the next day. Once situated in the Gulf of Mexico, Hilda strengthened into a hurricane and began a slow trawl northward, rapidly intensifying to its peak intensity with winds of 150 mph (240 km/h) on October 1, making it a Category 4 hurricane equivalent. Slight weakening occurred as Hilda made landfall on the southern Louisiana coast on October 3. After reaching land, the hurricane took a sharp turn eastward and rapidly weakened as a result of land interaction and the presence of cool, dry air. The weakened remnants of Hilda merged with a cold front a day after landfall and dissipated on October 5. Originating near Cuba, the cyclone intensified while moving through the Gulf of Mexico, and became a Category 4 hurricane in the Gulf of Mexico before striking Louisiana in early October. In combination with a frontal zone located across the Southeast United States, the hurricane spread heavy rains through the South through the Carolinas into the Mid-Atlantic States. Hilda led to significant damage to oil platforms in the Gulf of Mexico, as well as $126 million (1964 USD) in damage, and 38 deaths. ==Meteorological history== The origins of Hilda can be definitively traced back to a tropical wave that trekked across the western Caribbean Sea during the last week of September. However, a loosely defined mass of clouds east of the Lesser Antilles on September 23 was potentially associated with the formation of Hilda. Tracking westward, the area of convection gradually intensified, with hints at a well-defined circulation as the system tracked over Haiti on September 27.〔 By 1200 UTC on September 28, the disturbance had become sufficiently defined to be classified as a tropical depression south of Cuba. Tracking generally westward,〔 the depression crossed Cape San Antonio, Cuba on September 29, intensifying to tropical storm strength in the meanwhile before moving into the northern Yucatán Channel. Favorable conditions for tropical cyclone development in the western Caribbean, including the presence of abnormally high sea surface temperatures, allowed for the further strengthening of Hilda.〔 Hilda's crossing of western Cuba slightly disrupted the intensification of the tropical cyclone, but strengthening resumed shortly thereafter.〔 Upon reaching the Gulf of Mexico later of September 29, Hilda began to track very slowly at an average speed of ,〔 later meeting the threshold of hurricane intensity at 1200 UTC on September 30. During that time, atmospheric conditions over the Gulf of Mexico rapidly improved; a preexisting belt of strong wind shear, which would have inhibited further cyclonic strengthening, disintegrated coincident with Hilda's passage of the gulf.〔 Rapid intensification ensued on October 1, and by 0600 UTC that day Hilda became a major hurricane. Twelve hours later, the hurricane reached its peak intensity with maximum sustained winds of 150 mph (240 km/h) and a minimum barometric pressure of 941 mbar (hPa; 27.79 inHg) based on reconnaissance flights.〔 During this phase the storm was centered roughly south of New Orleans, Louisiana.〔 Around the same time, an abnormally strong trough centered over Mississippi began to sharply curve the forward motion of Hilda towards the north. Following peak intensity, further strengthening was inhibited due to the emergence of a high pressure area over the United States Gulf Coast. The presence of this system injected dry air into Hilda, gradually weakening the hurricane. The once prominent eye of the storm clouded over as a result of this advection. During the evening hours of October 3,〔 Hilda made landfall on the central Louisiana coast with a minimum pressure of 950 mbar (hPa; 28.06 inHg) and maximum sustained winds of , making it equivalent to a Category 3 hurricane on the modern-day Saffir–Simpson hurricane wind scale. Rapid weakening followed landfall as a result of the surrounding cold air;〔 by 0600 UTC on October 4, Hilda had been downgraded to tropical storm intensity. The same area of high pressure which had weakened the tropical cyclone later forced Hilda eastward,〔〔 resulting in the storm's merging with a cold front and thus transitioning into an extratropical cyclone later that day.〔 These extratropical remnants continued to track eastward before they were last noted near Jacksonville, Florida on October 5. 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「Hurricane Hilda」の詳細全文を読む スポンサード リンク
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