|
Typhoon Dianmu, known in the Philippines as Typhoon Helen, was a powerful typhoon that struck southeastern Japan during the 2004 Pacific typhoon season. The name Dianmu is the name of the goddess of thunder and lightning in Chinese folklore.〔 Dianmu formed on June 13 and moved west-northwest where it rapidly strengthened to typhoon status on June 16. Dianmu then strengthened to a 285 km/h (180 mph) typhoon, making it one of nine typhoons to reach that intensity since 1990 and equaled its power with Typhoon Chaba as the strongest typhoons of the 2004 season. After reaching peak intensity, Dianmu turned northwest before skirting the minor Japanese islands and making landfall in Japan as a tropical storm. Dianmu then became extratropical on June 21. Dianmu caused four fatalities and considerable damage across southern and eastern Japan.〔 Damage amounted to USD$68.3 million. Two more fatalities were also reported in neighboring South Korea. ==Meteorological history== An area of disturbed weather formed on June 11 within a monsoon trough southeast of Palau. Satellite imagery showed the disturbance beginning to acquire a low level circulation as the system was within a favorable area for tropical development. As the system began to strengthen, the Joint Typhoon Warning Center issued its first warning on the system as it strengthen to a tropical depression on June 13.〔 Moving westward, Tropical Depression 09W continued to strengthen and at on June 14, the Joint Typhoon Warning Center and the Japan Meteorological Agency upgraded the depression to tropical storm status. After becoming a tropical storm, Dianmu remained stationary west of Yap where it continued to strengthen.〔 The Japan Meteorological Agency upgraded the storm to typhoon status at 1373 UTC.〔 while the Joint Typhoon Warning Center upgraded the storm to typhoon status at 1800 UTC. Dianmu then moved north-northwestward at speeds between 6-9 kts (11–17 km/h, 7-10 mph) as it winds reached 241 km/h (150 mph), prompting the Joint Typhoon Warning Center to upgrade the storm to supertyphoon status on June 15. The following day, Dianmu continued northward as the storm reached category 5 status. At the same time, the storm entered the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) area of responsibility and was given the name Helen.〔 Dianmu reached its maximum intensity as its winds reached up to 285 km/h (180 mph) and the barometric pressure fell to 915 millibars. The JMA assessed the typhoon attaining a 10-minute peak of 185 km/h (115 mph) winds.〔 After maintaining Supertyphoon status for 42 hours, the storm began to weaken as it swung westward. The typhoon briefly regained supertyphoon status on June 18 before finally weakening again a few hours later. The next day, Dianmu swung northward as the center was located southeast of Okinawa. As it turned northward, dry air entered the storm causing the center to become ragged and eventually resulted in the storm weakening further as the winds dropped to on June 19.〔 On June 20, the center of Dianmu bypassed Okinawa by to the east as the storm continued to weaken. Satellite imagery showed the storm losing its deep convection and significant outflow and its winds dropped to 145 km/h (90 mph). As the storm approached Japan, it interacted with a trough which was position northwest of the storm. The resulting interaction with the trough caused the storm to drop below typhoon status. As the storm edged closer to Japan, it began to gradually take on the characteristics of an extratropical cyclone before it made its first landfall in Shikoku before making its second landfall in Honshū on June 21. The Joint Typhoon Warning Center issued its final advisory on Dianmu at 1800 UTC while the JMA continued to issue advisories until June 23.〔 The extratropical remnants of Dianmu then dissipated over the Bering Sea on June 25. 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「Typhoon Dianmu (2004)」の詳細全文を読む スポンサード リンク
|