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The 1947 Fort Lauderdale hurricane was an intense tropical cyclone that affected the Bahamas, southernmost Florida, and the Gulf Coast of the United States in September 1947. The fourth Atlantic tropical cyclone of the year, it formed in the eastern Atlantic Ocean on September 4, becoming a hurricane, the third of the 1947 Atlantic hurricane season, less than a day later. After moving south by west for the next four days, it turned to the northwest and rapidly attained strength beginning on September 9. It reached a peak intensity of on September 15 while approaching the Bahamas. In spite of contemporaneous forecasts that predicted a strike farther north, the storm then turned to the west and poised to strike South Florida, crossing first the northern Bahamas at peak intensity. In the Bahamas, the storm produced a large storm surge and heavy damage, but with no reported fatalities. A day later, the storm struck South Florida as a Category 4 hurricane, its eye becoming the first and only of a major hurricane to strike Fort Lauderdale. In Florida, advance warnings and stringent building codes were credited with minimizing structural damage and reducing loss of life to 17 people, but nevertheless widespread flooding and coastal damage resulted from heavy rainfall and high tides. Many vegetable plantings, citrus groves, and cattle were submerged or drowned as the storm exacerbated already high water levels and briefly threatened to breach the dikes surrounding Lake Okeechobee. However, the dikes held firm, and evacuations were otherwise credited with minimizing the potential death toll. On the west coast of the state, the storm caused further flooding, extensive damage south of the Tampa Bay Area, and the loss of a ship at sea. On September 18, the hurricane entered the Gulf of Mexico and threatened the Florida Panhandle, but later its track moved farther west than expected, ultimately leading to a landfall southeast of New Orleans, Louisiana. Upon making landfall, the storm killed 34 people on the Gulf Coast of the United States and produced a storm tide as high as , flooding millions of square miles and destroying thousands of homes. The storm was the first major hurricane to test Greater New Orleans since 1915, and the widespread flooding that resulted spurred flood-protection legislature and an enlarged levee system to safeguard the flood-prone area. In all, the powerful storm killed 51 people and caused $110 million (1947 US$) in damage. ==Meteorological history== Hurricane Four was first monitored as an area of low pressure over French West Africa on September 2, 1947. Steadily tracking westward, the system was quickly classified as a depression before moving into the Atlantic Ocean near Dakar, Senegal, on September 4. Shortly thereafter, weather agencies lost track of the system over water due to a lack of ships in the region. However, later analysis determined that the cyclone obtained tropical storm status, with maximum sustained winds of , during the morning of September 5. The storm gradually intensified as it tracked nearly due west, but then maintained an intensity of for nearly five days, taking a west-southwest turn on September 7 before turning to the northwest two days later, when the steamship ''Arakaka'' provided confirmation of its existence.〔〔 Another few days later, the cyclone began to intensify more rapidly as its forward speed increased; between September 10 and 15, reconnaissance missions by the United States Navy began monitoring the hurricane.〔 At 1500 UTC on September 11, a navy aircraft first penetrated the storm; in less than 24 hours, the storm rapidly strengthened into the equivalence of a Category 1 hurricane on the Saffir–Simpson Hurricane Scale, and shortly afterward attained peak winds of , roughly 18 hours after being classified a tropical storm, as another aircraft registered a barometric pressure of 977 mb (28.84 inHg), a drop of 22 mb in 24 hours. On September 13, another airplane at 1930 UTC confirmed that the storm had deepened further to 952 mb (28.11 inHg) and its eye shrunk to ;〔 by that time the hurricane had reached high-end Category 3 intensity, and intensified into a Category 4 hurricane six hours later.〔 The same mission reported a double eyewall, a feature replaced by a large eye by the time the storm hit the Bahamas and Florida.〔 The next day, the storm attained the minimum pressure, 938 mb (27.70 inHg), recorded by aircraft reconnaissance during its life span,〔 peaking in intensity as a strong Category 4 hurricane.〔 On September 15, however, the storm lost this intensity. Early on September 16, as its movement slowed greatly and turned westward near the northern Bahamas, the cyclone weakened into a Category 3 hurricane with winds of .〔 Following the phonetic alphabet from World War II,〔 the U.S. Weather Bureau office in Miami, Florida, which then worked in conjunction with the military, named the storm George, though such names were apparently informal and did not appear in public advisories until 1950, when the first Atlantic storm to be so designated was Hurricane Fox.〔 While retaining its intensity, the storm, its northwesterly course having been blocked by a ridge of high pressure,〔(【引用サイトリンク】url=http://docs.lib.noaa.gov/rescue/dwm/data_rescue_daily_weather_maps.html )〕 crossed the northern portion of the Abaco Islands, where on Elbow Cay the Hope Town weather station simultaneously estimated winds of and recorded 960.7 mb (28.37 inHg) as the center passed just to the north.〔〔 Until 2014, the cyclone was classified as a Category 5 hurricane in the northern Bahamas, based largely upon the observation from Elbow Cay; however, this wind was eventually determined to be unrepresentative of the intensity. (Visual estimates of wind speed, particularly early in the era of modern reconnaissance, were sometimes unreliable.) About 24 hours later on September 17, it made landfall near Fort Lauderdale, Florida, as a Category 4 hurricane with maximum sustained winds near .〔 To this date, the hurricane remains the only major hurricane to have struck Broward County, Florida, at that strength,〔 and the only one to pass directly over the county seat of Fort Lauderdale,〔 though the 1926 Miami hurricane and Hurricane King caused significant damage in the county. About 1700 UTC, the cyclone produced peak gusts of and sustained winds of at Hillsboro Inlet Light near Pompano Beach, Florida;〔 the gust was the highest measured wind speed recorded in the state of Florida until 1992, when Hurricane Andrew produced a gust of at Perrine.〔 The station also reported a pressure of 947.2 mb (27.97 inHg), the lowest during the passage of the storm over Florida,〔 though Fort Lauderdale, in the eye to the south, reported higher pressures; winds at the lighthouse briefly lulled as the center passed nearby, while Fort Lauderdale reported a one-hour lull.〔〔 Unusually, the lowest pressures occurred not in the center of the eye, but near its northern edge, suggesting the influence of eyewall mesovortices.〔 The hurricane moved slowly inland near ,〔 and it diminished to a Category 2 hurricane over the Everglades.〔 Early on September 18, the cyclone entered the Gulf of Mexico near Naples, producing wind gusts of at Sanibel Island Light near Fort Myers.〔 Once over water, the hurricane had diminished to about ;〔 though no further reconnaissance missions were dispatched to estimate its intensity over the Gulf of Mexico,〔 it is believed to have begun reintensifying as it turned west-northwest and its forward motion increased to .〔〔 On September 19, the hurricane moved ashore over Saint Bernard Parish, Louisiana, as a high-end Category 2 hurricane with . The hurricane quickly weakened as it moved over the New Orleans metropolitan area,〔 although its strong winds gusted to in New Orleans. The eye passed over Baton Rouge, the state capital, between 2000 and 2020 UTC,〔 with anemometers registering sustained winds of at 2045 UTC.〔 On September 20, the storm rapidly weakened to a tropical depression over northeastern Texas, but the remnant circulation turned northeast over southeastern Oklahoma and northwest Arkansas. On September 21, it dissipated over southern Missouri.〔 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「1947 Fort Lauderdale hurricane」の詳細全文を読む スポンサード リンク
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