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Hurricane Norbert is tied with Hurricane Jimena as the strongest tropical cyclone strike the west coast of Baja California Sur in recorded history. The fifteenth named storm, seventh hurricane, and second major hurricane of the 2008 hurricane season, Norbert originated as a tropical depression from a tropical wave south of Acapulco on October 3. Strong wind shear initially prevented much development, but the cyclone encountered a more favorable environment as it moved westward. On October 5, the National Hurricane Center (NHC) upgraded the depression to Tropical Storm Norbert, and the system intensified further to attain hurricane intensity by October 6. After undergoing a period of rapid deepening, Norbert reached its peak intensity as a Category 4 on the Saffir–Simpson hurricane wind scale, with maximum sustained winds of 135 mph (215 km/h) and a minimum barometric pressure of 945 mbar (hPa; 27.91 inHg). As the cyclone rounded the western periphery of a subtropical ridge over Mexico, it began an eyewall replacement cycle which led to steady weakening. Completing this cycle and briefly reintensifying into a major hurricane, a Category 3 or higher on the Saffir–Simpson hurricane wind scale, Norbert moved ashore Baja California Sur as a Category 2 hurricane late on October 11. After a second landfall at a weaker intensity the following day, the system quickly weakened over land and dissipated that afternoon. In preparation for the cyclone, the NHC issued hurricane warnings for coastal regions of the Baja California Peninsula. Residents living in low-lying areas and flood-prone regions were advised to evacuate, and beach-goers were warned to stay out of the water. Upon landfall, the hurricane produced waves in excess of . Though the strongest winds observed were less than hurricane intensity, heavy rainfall as a result of Norbert lead to substantial damage. In Baja California Sur, roughly 5,000 homes sustained major damage; the heaviest-impacted municipality, Comondú, reported 16,000 homes affected. Thousands of people were forced into shelters, and many trees were blown down by strong winds. A total of 25 fatalities occurred in Sonora, 5 of which occurred in Álamos, where excessive rainfall caused a majority of the town to become flooded; homes were submerged to their roofs and many trees were downed. The hurricane severely impacted the fishing industry in Sinaloa, while thousands of residents were left homeless. In the United States, Norbert produced minimal rainfall. In the aftermath of the storm, many towns and municipalities were declared disaster areas. Overall, Norbert inflicted $98.5 million (2008 USD) in damage. ==Meteorological history== The origins of Norbert were from a tropical wave that crossed Central America on September 26 and September 27. An area of disturbed weather formed near the Gulf of Tehuantepec on September 28,〔 which at that time was mentioned on the Tropical Weather Outlook (an outlook issued every six hours during hurricane season by the NHC that notes the possibility of tropical cyclogenesis during the next 48 hours).〔 Drifting westward off the coast of Mexico, the system initially consisted of a broad low pressure area and an area of disorganized convection. It slowly organized for several days, and by early on October 4 the system developed enough organized convection to be classified as Tropical Depression Fifteen; at that point, it was located about south of Acapulco. The depression was located over an area of warm water temperatures and moderate vertical wind shear, and as such was forecast to intensify gradually. About six hours after forming, the circulation of the depression became exposed from the deep convection, due to the wind shear. At the same time, two tropical cyclone forecast models predicted the tropical cyclone formation of a larger disturbance to the southeast of the depression. One model predicted the new cyclone to absorb the depression, although most other models forecast for the depression to remain the dominant system. By early on October 5, deep convection developed and organized around the center of the depression, and satellite intensity estimates using the Dvorak technique suggested that the system had tropical storm force-winds; as a result, the NHC upgraded the depression to Tropical Storm Norbert, about south of Zihuatanejo. Norbert slowly intensified, and was upgraded to a hurricane on October 6 as very deep atmospheric convection remained stable despite easterly wind shear. On October 7, Hurricane Norbert reached Category 2 intensity on the Saffir-Simpson Hurricane Scale while Norbert developed well-defined and closed eyewall as seen in microwave imagery. Overnight on October 8, an eye appeared on infrared satellite, indicating that Norbert was intensifying and the storm was upgraded to a major hurricane respectively. Continuing to rapidly strengthen over warm sea surface temperatures, it reached Category 4 status late on October 8, after intensifying 45 mph (75 km/h) over the previous 24 hours. The storm peak intensity was 135 mph (215 km/h) and a peak pressure of 945 mbar (hPa; 27.91 inHg) while located south of Cabo San Lucas, Mexico. The peak intensity of Norbert is uncertain as aircraft-based wind speed observations were lower than estimates via Dvorak Technique.〔 However, the cloud pattern became less impressive early on October 9, and was thus downgraded into a Category 3 hurricane, with winds of 125 mph (205 km/h) as it moved. The eye began to erode and as such Norbert underwent an eyewall replacement cycle, where one eye is replaced by another. As a result, when Hurricane Hunters investigated the storm later that day, they found that Norbert had weakened considerably. At that time, it was downgraded into a weak Category 1 hurricane on October 9.〔 On October 10, Norbert turned towards the north while slowing down as it reached the western edge of a subtropical ridge. In an area of light wind shear, Norbert began to re-intensify as the eyewall replacement cycle completed. The cyclone turned to the north-northeast due to a mid to upper level trough that was moving over the Southwest United States. Norbert managed to restrengthen into a Category 3 hurricane on 0600 UTC October 11, and made landfall as a Category 2 hurricane near Puerto Charley.〔 The next day, Norbert struck southern Sonora at Category 1 intensity.〔 Norbert rapidly dissipated by October 12 while inland over Mexico.〔 Norbert was a Category 2 hurricane at landfall and is currently tied with Hurricane Jimena for the strongest storm to strike the west coast of the Baja California Peninsula. 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 Norbert (2008)」の詳細全文を読む スポンサード リンク
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