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Hurricane Alicia was the costliest tropical cyclone in the Atlantic since Hurricane Agnes in 1972. Alicia was the third depression, the first tropical storm, and the only major hurricane of the 1983 Atlantic hurricane season. It struck Galveston and Houston, Texas directly, causing $2.6 billion (1983 USD; US$ ) in damage and killing 21 people; this made it the worst Texas hurricane since Hurricane Carla in 1961.〔 In addition, Alicia was the first billion-dollar tropical cyclone in Texas history. Hurricane Alicia was the first hurricane to hit the United States mainland since Hurricane Allen in August 1980. The time between the two storms totaled three years and eight days (1,103 days). Hurricane Alicia became the last major hurricane (Category 3 or higher) to strike Texas until the stronger Hurricane Bret in 1999 made landfall. Alicia was the first storm for which the National Hurricane Center issued landfall probabilities.〔 Hurricane Alicia was notable for the delayed post storm evacuation of Galveston Island (since the eye of the storm traveled the evacuation route up Interstate 45 from Galveston to Houston). The hurricane was also notable for the shattering of many windows in downtown Houston by loose gravel from the roofs of new skyscrapers and by other debris, prompting changes to rooftop construction codes. ==Meteorological history== The origins of Hurricane Alicia were from a cold front that extended from New England through the central Gulf of Mexico. On August 14, mesoscale low-pressure area developed off the Alabama and Mississippi coastlines. Around 0100 UTC on August 15, the low had maintained convection, or area of thunderstorms, for 12 hours, as well as a circulation for six hours; as a result, the National Hurricane Center (NHC) began issuing Dvorak classifications on the system. By a few hours later, the deep convection became organized in the circulation's southern semicircle, which prompted a Hurricane Hunters flight into the system. At 1200 UTC that day, the system developed into Tropical Depression Three about 350 miles (560 km) south-southwest of the Mississippi River Delta. A few hours later, the Hurricane Hunters confirmed its development. Such development along the tail end of a cold front is more typical earlier or later in the hurricane season. After becoming a tropical cyclone, the depression was moving slowly westward, due to a ridge to its north.〔 A Hurricane Hunters flight late on August 15 reported that the depression reached winds of 50 mph (80 km/h); as a result, the NHC upgraded the cyclone to Tropical Storm Alicia. At the time of its upgrade, the storm was located in an area of higher than normal atmospheric pressure, although conditions favored further development. Due to high pressures surrounding the storm, Alicia was a smaller than normal tropical cyclone; as a result, it produced stronger than normal winds, in comparison to its minimum central pressure.〔 The storm continued slowly to the west-northwest, and by August 17 attained hurricane status, about 160 miles (255 km) southeast of Galveston, Texas. Shortly thereafter, an eye became visible on radar, as the hurricane executed several small loops.〔 Its slow movement over warm waters, in addition to an anticyclone becoming established over the hurricane, caused Alicia to undergo rapid deepening.〔 At 0600 UTC on August 18, the winds reached 115 mph (185 km/h), just before Alicia made landfall about southwest of Galveston, Texas. Upon moving ashore, the gale-force winds extended from the center, and hurricane force winds spread across an area from Freeport to northeast. Its atmospheric pressure was 962 mbar (hPa; 28.41 inHg) around the time of landfall, and radar imagery indicated the presence of a rare double-eye structure.〔 Alicia quickly weakened, passing over central Houston with sustained winds of 80 mph (130 km/h). It accelerated toward the northwest, weakening to tropical storm status late on August 18 and to tropical depression status twelve hours later. Tropical Depression Alicia moved into Oklahoma and interacted with an approaching frontal trough. By 0600 UTC on August 20, Alicia had transitioned into an extratropical cyclone over northwestern Oklahoma, and by the next day it was no longer identifiable after merging with the trough over eastern Nebraska.〔 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 Alicia」の詳細全文を読む スポンサード リンク
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