Accession Number : ADA561929


Title :   Annual Tropical Cyclone Report 2011


Descriptive Note : Annual rept. 1 Jan-31 Dec 2011


Corporate Author : JOINT TYPHOON WARNING CENTER PEARL HARBOR HI


Personal Author(s) : Angove, Michael D ; Falvey, Robert J ; Darlow, James W


Full Text : http://www.dtic.mil/dtic/tr/fulltext/u2/a561929.pdf


Report Date : 24 May 2012


Pagination or Media Count : 112


Abstract : This edition of the Annual Tropical Cyclone Report (ATCR) documents the TC season and details operationally or meteorologically significant cyclones noted within the JTWC Area of Responsibility. Details are provided to describe operational impacts from tropical cyclones as well as significant challenges and/or shortfalls in the TC warning system. These details are provided to serve as input for future research and development efforts. Below average tropical cyclone activity continued in the western North Pacific Ocean, continuing a trend that started in 2005, with only 27 TCs observed compared to the long term average of 31. Unlike the previous year, there were four cyclones that reached super typhoon intensity. The TC formation region was displaced north and west again in 2011, a characteristic common during La Nina conditions. Several of these early to mid-season forming TCs exhibited S shaped, looping, or generally erratic tracks, with numerous passages near or over Okinawa. In fact, Super Typhoon Songda (04W) passed just west of Kadena Air Base and destroyed the WSR-88D Doppler Weather Radar. As of the writing of this report, the 18 Air Wing at Kadena AB had procured the funding necessary to replace the radar. The Southern Hemisphere activity also continued a below normal trend, with 21 cyclones observed compared to the long term average of 28 and the Northern Indian Ocean experienced near normal activity with 6 cyclones. Weather satellite data remained the mainstay of the TC reconnaissance mission to support the JTWC.


Descriptors :   *TROPICAL CYCLONES , METEOROLOGICAL DATA , PACIFIC OCEAN , TABLES(DATA)


Subject Categories : Atmospheric Physics
      Meteorology


Distribution Statement : APPROVED FOR PUBLIC RELEASE