|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.
The United States Navy (USN) is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. It is the largest and most capable navy in the world and it has been estimated that in terms of tonnage of its active battle fleet alone, it is larger than the next 13 navies combined, which includes 11 U.S. allies or partner nations. with the highest combined battle fleet tonnage and the world's largest aircraft carrier fleet, with eleven in service, and two new carriers under construction. With 319,421 personnel on active duty and 99,616 in the Ready Reserve, the Navy is the third largest of the service branches. It has 282 deployable combat vessels and more than 3,700 operational aircraft as of March 2018, making it the second-largest air force in the world, after the United States Air Force.
The United States Air Force (USAF) is the aerial and space warfare service branch of the United States Armed Forces. It is one of the five branches of the United States Armed Forces, and one of the seven American uniformed services. Initially formed as a part of the United States Army on 1 August 1907, the USAF was established as a separate branch of the U.S. Armed Forces on 18 September 1947 with the passing of the National Security Act of 1947. It is the youngest branch of the U.S. Armed Forces, and the fourth in order of precedence. The USAF is the largest and most technologically advanced air force in the world. The Air Force articulates its core missions as air and space superiority, global integrated intelligence, surveillance, and reconnaissance, rapid global mobility, global strike, and command and control.
Pearl Harbor is a lagoon harbor on the island of Oahu, Hawaii, west of Honolulu. It has been long visited by the Naval fleet of the United States, before it was acquired from the Hawaiian Kingdom by the U.S. with the signing of the Reciprocity Treaty of 1875. Much of the harbor and surrounding lands is now a United States Navy deep-water naval base. It is also the headquarters of the United States Pacific Fleet. The U.S. government first obtained exclusive use of the inlet and the right to maintain a repair and coaling station for ships here in 1887. The attack on Pearl Harbor by the Empire of Japan on December 7, 1941, was the immediate cause of the United States' entry into World War II.
Its U.S. Navy components are aligned with Naval Meteorology and Oceanography Command.
The Naval Meteorology and Oceanography Command (COMNAVMETOCCOM) or CNMOC, serves as the operational arm of the Naval Oceanography Program. Headquartered at the Stennis Space Center in Mississippi, CNMOC is an echelon three command reporting to United States Fleet Forces Command (USFLTFORCOM). CNMOC's claimancy is globally distributed, with assets located on larger ships, shore facilities at fleet concentration areas, and larger production centers in the U.S.
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 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.
Guam is an unincorporated and organized territory of the United States in Micronesia in the western Pacific Ocean. It is the easternmost point and territory of the United States, along with the Northern Mariana Islands. The capital city of Guam is Hagåtña and the most populous city is Dededo. The inhabitants of Guam are called Guamanians, and they are American citizens by birth. Indigenous Guamanians are the Chamorros, who are related to other Austronesian natives of Eastern Indonesia, the Philippines, and Taiwan. Guam has been a member of the Pacific Community since 1983.
The Department of Defense is an executive branch department of the federal government charged with coordinating and supervising all agencies and functions of the government concerned directly with national security and the United States Armed Forces. The department is the largest employer in the world, with nearly 1.3 million active duty servicemen and women as of 2016. Adding to its employees are over 826,000 National Guardsmen and Reservists from the four services, and over 732,000 civilians bringing the total to over 2.8 million employees. Headquartered at the Pentagon in Arlington, Virginia, just outside Washington, D.C., the DoD's stated mission is to provide "the military forces needed to deter war and ensure our nation's security".
The National Weather Service (NWS) is an agency of the United States federal government that is tasked with providing weather forecasts, warnings of hazardous weather, and other weather-related products to organizations and the public for the purposes of protection, safety, and general information. It is a part of the National Oceanic and Atmospheric Administration (NOAA) branch of the Department of Commerce, and is headquartered in Silver Spring, Maryland, within the Washington metropolitan area. The agency was known as the United States Weather Bureau from 1890 until it adopted its current name in 1970.
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 Peninsular 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.
Typhoon Karen was the most powerful tropical cyclone to strike the island of Guam, and has been regarded as one of the most destructive events in the island's history. It was first identified as a tropical disturbance on November 6, 1962, well to the southeast of Truk. Over the following two days, the system tracked generally northward and quickly intensified. Karen became a tropical storm late on November 7, and within two days it explosively intensified into a Category 5-equivalent super typhoon on the Saffir–Simpson scale. Turning westward, the typhoon maintained its intensity and struck Guam with winds of 280 km/h (175 mph) on November 11. Once clear of the island, it strengthened slightly and reached its peak intensity on November 13 with winds of 295 km/h (185 mph) and a barometric pressure of 894 mb. The storm then gradually turned northward as it weakened, brushing the Ryukyu Islands on November 15, before moving east-northeastward over the open waters of the Pacific. Karen continued to weaken and transitioned into an extratropical cyclone on November 17 before losing its identity the following day between Alaska and Hawaii.
The 1995 Base Realignment and Closure Commission preliminary list was released by the United States Department of Defense in 1995 as part of the Base Realignment and Closure Commission. It recommended closing 32 major United States military bases.
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.
The National Hurricane Center (NHC) is the division of the United States' National Weather Service responsible for tracking and predicting tropical weather systems between the Prime Meridian and the 140th meridian west poleward to the 30th parallel north in the northeast Pacific Ocean and the 31st parallel north in the northern Atlantic Ocean. The agency, which is co-located with the Miami branch of the National Weather Service, is situated on the campus of Florida International University in University Park, Florida.
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 World Meteorological Organization (WMO) is an intergovernmental organization with a membership of 192 Member States and Territories. Its current Secretary-General is Petteri Taalas and the President of the World Meteorological Congress, its supreme body, is David Grimes. The Organization is headquartered in Geneva, Switzerland.
A tropical cyclone is a rapidly rotating storm system characterized by a low-pressure center, a closed low-level atmospheric circulation, strong winds, and a spiral arrangement of thunderstorms that produce heavy rain. Depending on its location and strength, a tropical cyclone is referred to by different names, including hurricane, typhoon, tropical storm, cyclonic storm, tropical depression, and simply cyclone. A hurricane is a tropical cyclone that occurs in the Atlantic Ocean and northeastern Pacific Ocean, and a typhoon occurs in the northwestern Pacific Ocean; in the south Pacific or Indian Ocean, comparable storms are referred to simply as "tropical cyclones" or "severe cyclonic storms".
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 and 14 typhoons, compared to the average of 27 and 17 respectively. had no official bounds; it ran year-round in 2007, 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.
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.
Tropical Storm Mekkhala was recognised as the 16th Tropical Storm of the 2008 Pacific typhoon season by the Japan Meteorological Agency who are the Regional Specialized Meteorological Centre for the North Western Pacific Ocean. The Joint Typhoon Warning Center (JTWC) have also recognised Mekkhala as the 20th tropical depression, and the 18th tropical storm of the 2008 Pacific typhoon season.
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 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. Moreover, the season had an index total Accumulated Cyclone Energy (ACE) of 115, which is the second lowest in the basin after 1999. It was also the fourth consecutive year with a below average ACE index.
Typhoon Nida, known in the Philippines as Tropical Storm Vinta, was the most intense tropical cyclone in the Northwest Pacific Ocean during the 2000s, tied with Jangmi in 2008.
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 the most active Pacific typhoon season since 2004, as well as the deadliest since 1975. 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 the typhoon strength.
The 2014 Pacific typhoon season was a slightly below average season, featuring 23 tropical storms, 11 typhoons, and 8 super typhoons. The season's peak months August and September saw minimal activity caused by an unusually strong and a persistent suppressing phase of the Madden–Julian oscillation (MJO). The season ran throughout 2014, though most tropical cyclones typically develop between May and October. The season began with the development of Tropical Storm Lingling on January 18, and ended after Tropical Storm Jangmi which dissipated on January 1 of the next year.
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 2017 Pacific typhoon season was a below-average season in terms of Accumulated Cyclone Energy and the number of typhoons and super typhoons, and the first and latest since the 1977 season to not produce a Category 5-equivalent typhoon on the Saffir-Simpson scale. The season produced a total of 27 named storms, 11 typhoons, and only two super typhoons, making it an average season in terms of storm numbers. It was an event in the annual cycle of tropical cyclone formation, in which tropical cyclones form in the western Pacific Ocean. The season runs throughout 2017, though most tropical cyclones typically develop between May and October. The season's first named storm, Muifa, developed on April 25, while the season's last named storm, Tembin, dissipated on December 26. This season also featured the latest occurrence of the first typhoon of the year since 1998, with Noru reaching this intensity on July 23.
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.
Typhoon Haiyan's meteorological history began with its origins as a tropical disturbance east-southeast of Pohnpei and lasted until its degeneration as a tropical cyclone over Southern China. The thirteenth typhoon of the 2013 Pacific typhoon season, Haiyan originated from an area of low pressure several hundred kilometers east-southeast of Pohnpei in the Federated States of Micronesia on November 2. Tracking generally westward, environmental conditions favored tropical cyclogenesis and the system developed into a tropical depression the following day. After becoming a tropical storm and attaining the name Haiyan at 0000 UTC on November 4, the system began a period of rapid intensification that brought it to typhoon intensity by 1800 UTC on November 5. By November 6, the Joint Typhoon Warning Center (JTWC) assessed the system as a Category 5-equivalent super typhoon on the Saffir-Simpson hurricane wind scale; the storm passed over the island of Kayangel in Palau shortly after attaining this strength.
Hurricane Genevieve, also referred to as Typhoon Genevieve, was the fourth-most intense tropical cyclone of the North Pacific Ocean in 2014. A long-lasting system, Genevieve was the first one to track across all three northern Pacific basins since Hurricane Dora in 1999. Genevieve developed from a tropical wave into the eighth tropical storm of the 2014 Pacific hurricane season well east-southeast of Hawaii on July 25. However, increased vertical wind shear caused it to weaken into a tropical depression by the following day and degenerate into a remnant low on July 28. Late on July 29, the system regenerated into a tropical depression, but it weakened into a remnant low again on July 31, owing to vertical wind shear and dry air.
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.
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.