|Formed||May 1, 1959|
|Headquarters||Pearl Harbor, Hawaii|
|Parent agency|| United States Navy |
United States Air Force
The Joint Typhoon Warning Center (JTWC) is a joint United States Navy – United States Air Force command located in Pearl Harbor, Hawaii. The JTWC is responsible for the issuing of tropical cyclone warnings in the North-West Pacific Ocean, South Pacific Ocean, and Indian Ocean for all branches of the U.S. Department of Defense and other U.S. government agencies. Their warnings are intended for the protection of primarily military ships and aircraft as well as military installations jointly operated with other countries around the world.
Its U.S. Navy components are aligned with Naval Meteorology and Oceanography Command.
The origins of the Joint Typhoon Warning Center (JTWC) can be traced back to June 1945, when the Fleet Weather Center/Typhoon Tracking Center was established on the island of Guam, after multiple typhoons, including Typhoon Cobra of December 1944 and another typhoon in June 1945, had caused a significant loss of men and ships.At this time the centre was one of three Navy and two Air Force units responsible for tropical cyclone reconnaissance and warnings in the Pacific. Over the next few years the coordination of tropical warnings between the centres was at times difficult or impossible due to various communication problems. During 1958, the United States Department of Defense weather services and the Weather Bureau formed the Joint Meteorology Committee to the Pacific Command and proposed the formation of a joint Navy and Air Force center for typhoon analysis and forecasting. A committee was subsequently set up to study the issue which issued a report during January 1959, which gave recommendation that the center be set up. Based on the report and the conclusions reached at the March 1959 Annual Tropical Cyclone Conference, the Joint Meteorology Committee formally urged, The Commander in Chief, US Pacific Command (CINCPAC) to establish a Joint Typhoon Warning Center. The CINCPAC subsequently petitioned the Joint Chiefs of Staff, who gave permission for the centre to be set up effective May 1, 1959, under the command of the Fleet Weather Center's commander.
The JTWC initially consisted of ten people with two officers and three enlisted personnel provided by each service.It was required to provide warnings on all tropical cyclones between the Malay Peninsula and the International Dateline for US government agencies. They also had to determine reconnaissance requirements, prepare annual typhoon summaries, and conduct research into tropical cyclone forecasting and detection. In November 1962, Typhoon Karen destroyed the building housing the Fleet Weather Center/Joint Typhoon Warning Center. It relocated in a more typhoon-proof building in 1965. Between 1971 and 1976, CINCPAC gradually expanded out the JTWC's area of responsibility, to include the area between the International Dateline and the African coasts. In October 1978, the Fleet Weather Center/JTWC became the Navy Oceanographic Command Center/Joint Typhoon Warning Center and responsible for the whole oceanic environment, from the bottom of the ocean to the top of the atmosphere. The JTWC subsequently started issuing warnings for the Southern Hemisphere between the African coast and the International Dateline during October 1980. It was relocated to Pearl Harbor on January 1, 1999 due to the 1995 Base Realignment and Closure Commission round. During October 2011, the JTWC's name changed from the “Naval Maritime Forecast Center/Joint Typhoon Warning Center” to just the Joint Typhoon Warning Center, as it became a stand-alone command for the first time in its 52-year history.
A more modernized method for forecasting tropical cyclones had become apparent by the 1980s. Prior to the development of ATCF, the tools used by the Department of Defense to forecast tropical cyclone track were acetate, grease pencils, and disparate computer programs.The ATCF software was developed by the Naval Research Laboratory for the JTWC beginning in 1986, and used since 1988. It was adapted for use at the National Hurricane Center (NHC) in 1990.
JTWC adheres to the World Meteorological Organization's (WMO) rules for storm names and adheres to acknowledged guidelines for intensity of tropical cyclones and tropical storms, with the exception of using the U.S. standard of measuring sustained winds for 1-min instead of the 10-min span recommended by the WMO (see Saffir-Simpson Hurricane Scale). The JTWC is not one of the WMO designated Regional Specialized Meteorological Centres, nor one of its Tropical cyclone warning centres, as its main mission is to support the United States government agencies.JTWC monitors, analyzes, and forecasts tropical cyclone formation, development, and movement year round. Its area of responsibility covers 89% of the world's tropical cyclone activity.
The Center is manned by about 37 U.S. Air Force and Navy personnel.The JTWC uses several satellite systems and sensors, radar, surface and upper level synoptic data as well as atmospheric models to complete its mission.
The 2007 Pacific typhoon season was a below average season which featured 24 named storms, fourteen typhoons, and five super typhoons. It was an event in the annual cycle of tropical cyclone formation, in which tropical cyclones form in the western Pacific Ocean. The season ran throughout 2007, though most tropical cyclones typically develop between May and November. The season's first named storm, Kong-rey, developed on March 30, while the season's last named storm, Mitag, dissipated on November 27. The season's first typhoon, Yutu, reached typhoon status on May 18, and became the first super typhoon of the year on the next day.
A typhoon is a mature tropical cyclone that develops between 180° and 100°E in the Northern Hemisphere. This region is referred to as the Northwestern Pacific Basin, and is the most active tropical cyclone basin on Earth, accounting for almost one-third of the world's annual tropical cyclones. For organizational purposes, the northern Pacific Ocean is divided into three regions: the eastern, central, and western. The Regional Specialized Meteorological Center (RSMC) for tropical cyclone forecasts is in Japan, with other tropical cyclone warning centers for the northwest Pacific in Hawaii, the Philippines and Hong Kong. While the RSMC names each system, the main name list itself is coordinated among 18 countries that have territories threatened by typhoons each year.
The 1959 Pacific typhoon season was regarded as one of the most devastating years for Pacific typhoons on record, with China, Japan and South Korea sustaining catastrophic losses.
The 2008 Pacific typhoon season had no official bounds; it ran year-round in 2008, but most tropical cyclones tend to form in the northwestern Pacific Ocean between May and November. These dates conventionally delimit the period of each year when most tropical cyclones form in the northwestern Pacific Ocean.
Typhoon Sepat, known in the Philippines as Typhoon Egay, was the eighth tropical storm of the 2007 Pacific typhoon season that affected the Philippines and made landfall in Taiwan and Fujian.
An invest in meteorology is a designated area of disturbed weather that is being monitored for potential tropical cyclone development. Invests are designated by three separate United States forecast centers: the National Hurricane Center, the Central Pacific Hurricane Center, and the Joint Typhoon Warning Center.
The 2012 Pacific typhoon season was a fairly average but destructive season, though rather active since 2004. It produced 25 named storms, fourteen typhoons, and four intense typhoons. It was an event in the annual cycle of tropical cyclone formation, in which tropical cyclones form in the western Pacific Ocean. The season ran throughout 2012, though most tropical cyclones typically develop between May and October. The season's first named storm, Pakhar, developed on March 28, while the season's last named storm, Wukong, dissipated on December 29. The season's first typhoon, Guchol, reached typhoon status on June 15, and became the first super typhoon of the year on June 17.
The 2009 Pacific typhoon season was a below average season that spawned only 22 named storms, 13 typhoons, and five super typhoons. It was also recognized as the deadliest season in the Philippines for decades. The first half of the season was very quiet whereas the second half of the season was extremely active. The season's first named storm, Kujira, developed on May 3 while the season's last named storm, Nida, dissipated on December 3.
The 2010 Pacific typhoon season was the least active Pacific typhoon season on record, featuring only 14 named storms; seven of them strengthened into typhoons while one reached super typhoon intensity. The Pacific typhoon season during 2010 was in fact less active than the 2010 Atlantic hurricane season, the only such occurrence other than 2005. In the same year, the Pacific hurricane season broke the same record being the least active season on record. During the season no storms have made landfall in mainland Japan, the only second such occurrence since 1988. Also, all of the 14 named storms developed west of 150°E.
The 2011–12 Australian region cyclone season was a below average tropical cyclone season, with 7 cyclones forming rather than the usual 11. It began on 1 November 2011, and ended on 14 May 2012. The regional tropical cyclone operational plan defines a "tropical cyclone year" separately from a "tropical cyclone season"; the "tropical cyclone year" began on 1 July 2011 and ended on 30 June 2012.
The 2011 Pacific typhoon season was a slightly below average season that produced a total of 21 named storms, 8 typhoons, and four super typhoons. This season was much more active than the previous season, although both seasons were below the Pacific typhoon average of 26. The season ran throughout 2011, though most tropical cyclone tend to develop between May and October. The season's first named storm, Aere, developed on May 7 while the season's last named storm, Washi dissipated on December 19.
The 2013 Pacific typhoon season was a disastrous typhoon season. It was the most active Pacific typhoon season since 2004, as well as the deadliest since 1975. This season also featured one of the most powerful storms in recorded history. It was an above-average season with 31 named storms, 13 typhoons, and five super typhoons. The season's first named storm, Sonamu, developed on January 4 while the season's last named storm, Podul, dissipated on November 15. Most of the first seventeen named storms before mid-September were relatively weak, as only two of them reached typhoon intensity. Total damage amounted to at least $25.95 billion (USD), making it the third costliest Pacific typhoon season on record; behind 2018 and 2019.
The 2015 Pacific typhoon season was a slightly above average season that produced 27 tropical storms, 18 typhoons, and nine super typhoons. The season ran throughout 2015, though most tropical cyclones typically develop between May and November. The season's first named storm, Mekkhala, developed on January 15, while the season's last named storm, Melor, dissipated on December 17. The season saw at least one named tropical system forming in each of every month, the first time since 1965. Similar to the previous season, this season saw a high number of super typhoons. Accumulated cyclone energy (ACE) during 2015 was extremely high, the second highest since the 1970, and the 2015 ACE has been attributed in part to anthropogenic warming.
The 2016 Pacific typhoon season had the fifth-latest start for a Pacific typhoon season since reliable records began. It was an average season, with a total of 26 named storms, 13 typhoons, and six super typhoons. The season ran throughout 2016, though typically most tropical cyclones develop between May and October. The season's first named storm, Nepartak, developed on July 3, while the season's last named storm, Nock-ten, dissipated on December 28.
The practice of using names to identify tropical cyclones goes back several centuries, with storms named after places, saints or things they hit before the formal start of naming in each basin. Examples of such names are the 1928 Okeechobee hurricane and the 1938 New England hurricane. The system currently in place provides identification of tropical cyclones in a brief form that is easily understood and recognized by the public. The credit for the first usage of personal names for weather systems is given to the Queensland Government Meteorologist Clement Wragge, who named tropical cyclones and anticyclones between 1887 and 1907. This system of naming fell into disuse for several years after Wragge retired, until it was revived in the latter part of World War II for the Western Pacific. Over the following decades formal naming schemes were introduced for several tropical cyclone basins, including the North and South Atlantic, Eastern, Central, Western and Southern Pacific basins as well as the Australian region and Indian Ocean.
The Automated Tropical Cyclone Forecasting System (ATCF) is a piece of software originally developed to run on a personal computer for the Joint Typhoon Warning Center (JTWC) in 1988, and the National Hurricane Center (NHC) in 1990. ATCF remains the main piece of forecasting software used for the United States Government, including the JTWC, NHC, and Central Pacific Hurricane Center. Other tropical cyclone centers in Australia and Canada developed similar software in the 1990s. The data files with ATCF lie within three decks, known as the a-, b-, and f-decks. The a-decks include forecast information, the b-decks contain a history of center fixes at synoptic hours, and the f-decks include the various fixes made by various analysis center at various times. In the years since its introduction, it has been adapted to Unix and Linux platforms.
This timeline documents all of the events of the 2015 Pacific typhoon season. Most of the tropical cyclones formed between May and November. The scope of this article is limited to the Pacific Ocean, north of the equator between 100°E and the International Date Line. This area, called the Western Pacific basin, is the responsibility of the Japanese Meteorological Agency (JMA). They host and operate the Regional Specialized Meteorological Center (RSMC), located in Tokyo. The Japanese Meteorological Agency (JMA) is also responsible for assigning names to all tropical storms that are formed within the basin. However, any storm that enters or forms in the Philippine Area of Responsibility (PAR) will be named by the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) using a local name. Also of note - the Western Pacific basin is monitored by the United States' Joint Typhoon Warning Center (JTWC), which gives all Tropical depressions a number with a "W" suffix.
Severe Tropical Cyclone Amos was a strong tropical cyclone that affected the Fijian and Samoan Islands as well as Wallis and Futuna. Amos was first noted as Tropical Disturbance 17F during April 13, 2016 to the northwest of Fiji. The system subsequently moved south-eastwards towards the Fijian Islands, before it passed near or over Vanua Levu during April 16. After passing over Fiji, the system gradually developed further as it moved north-eastwards towards the Samoan Islands. The system was subsequently named Amos during April 20, after it had developed into a tropical cyclone and started to move north-westwards towards the island nation of Tuvalu.
Typhoon Songda was the sixth most intense tropical cyclone of the Northwest Pacific Ocean in 2016. Also known as the Ides of October storm, it struck the Pacific Northwest region of the United States and Canada as a powerful extratropical cyclone. Songda was the twentieth named storm and the ninth typhoon of the annual typhoon season. The system developed into a tropical storm south of Minamitorishima on October 8 and strengthened into a typhoon on October 10. Songda reached its peak intensity southeast of Japan late on October 11 at an unusually high latitude, before it became extratropical on October 13.
A tropical cyclone tracking chart is used by those within hurricane-threatened areas to track tropical cyclones worldwide. In the north Atlantic basin, they are known as hurricane tracking charts. New tropical cyclone information is available at least every six hours in the Northern Hemisphere and at least every twelve hours in the Southern Hemisphere. Charts include maps of the areas where tropical cyclones form and track within the various basins, include name lists for the year, basin-specific tropical cyclone definitions, rules of thumb for hurricane preparedness, emergency contact information, and numbers for figuring out where tropical cyclone shelters are open.