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Tropical Storm Norma was the fourteenth named tropical cyclone of the 1970 Pacific hurricane season. The storm formed off the coast of Mexico and intensified rapidly, peaking as a strong tropical storm on September 3 before starting a weakening trend which saw it dissipate before making landfall on Baja California. While the storm never made landfall, the remnants from the storm fueled the Labor Day Storm of 1970, which caused floods in Arizona that resulted in heavy damage and loss of life. The rainfall from this storm broke records, mostly for 24-hour rainfall totals. Despite not being tropical when the damages were done, Norma is considered to be the deadliest system in Arizona history.〔http://www.wrh.noaa.gov/psr/tropics/hurricanes.htm〕 ==Meteorological history== A tropical disturbance was first noted in a satellite picture taken on August 30. Soon after, a weak low pressure center associated with the system formed southwest of Acapulco, Mexico.〔http://docs.lib.noaa.gov/rescue/mwr/099/mwr-099-04-0286.pdf〕 The system later went through rapid intensification, becoming a tropical depression on August 31 and Tropical Storm Norma later that day. Initially with a loose organization, Norma continued to organize and strengthen, reaching its peak of on September 2. Satellite pictures showed cirrus outflow was greater in the tops of the feeder bands than in the eyewall chimney.〔 On September 3, Navy reconnaissance reported a 992 mbar pressure, Norma's lowest.〔 Shortly after the 992 mbar report, however, Norma began to weaken. The same recon that reported the and 992 mbar reading reported back with a mere some time after. Despite the sudden drop in winds, the minimum pressure remained around 994 mbar. The weakening became obvious on satellite presentation, which showed cool inflow and a sheet of stratocumulus clouds around the west semicircle extending under the storm clouds. Norma continued to weaken, degrading into a depression by September 4. At this point, the circulation forced moist and unstable maritime air into Arizona which resulted in disastrous floods during Labor Day along with a slow moving cold front. This system would become known as the Labor Day Storm of 1970. On September 5, a cloud spiral was still visible west of Baja California, but the storm's circulation dissipated, with the remnants of the storm finally dissipating on September 6, just before making landfall on Baja California.〔 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「Tropical Storm Norma (1970)」の詳細全文を読む スポンサード リンク
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