Tropical cyclones and subtropical cyclones are named by various warning centers to simplify communication between forecasters and the general public regarding forecasts, watches and warnings. The names are intended to reduce confusion in the event of concurrent storms in the same basin. Once storms develop sustained wind speeds of more than 33 knots, names are generally assigned to them from predetermined lists, depending on the basin in which they originate. Some tropical depressions are named in the Western Pacific, while tropical cyclones must contain a significant amount of gale-force winds before they are named in the Southern Hemisphere.
A Regional Specialized Meteorological Centre (RSMC) is responsible for the distribution of information, advisories, and warnings regarding the specific program they have a part of, agreed by consensus at the World Meteorological Organization as part of the World Weather Watch.
The 2007–08 Australian region cyclone season was a slightly below-average tropical cyclone season. The season began with an early start, with the formation of the first tropical cyclone on 29 July, which was only recognized as a tropical cyclone during post-season analysis. This was the second time that a tropical cyclone had formed during July. The other one was Cyclone Lindsay in the 1996–1997 season. The next tropical cyclone that formed was Cyclone Guba, which formed on 13 November with TCWC Port Moresby assigning the name Guba on 14 November, which was the first named storm within TCWC Port Moresby's area of responsibility since Cyclone Epi in June 2003. Guba was also the first cyclone to occur in the Queensland region in November since 1977.
An Australian region tropical cyclone is a non-frontal, low-pressure system that has developed within an environment of warm sea surface temperatures and little vertical wind shear aloft in either the Southern Indian Ocean or the South Pacific Ocean. Within the Southern Hemisphere there are officially three areas where tropical cyclones develop on a regular basis: the South-West Indian Ocean between Africa and 90°E, the Australian region between 90°E and 160°E, and the South Pacific basin between 160°E and 120°W. The Australian region between 90°E and 160°E is officially monitored by the Australian Bureau of Meteorology, the Indonesian Meteorology, Climatology, and Geophysical Agency, and the Papua New Guinea National Weather Service, while others like the Fiji Meteorological Service and the United States National Oceanic and Atmospheric Administration also monitor the basin. Each tropical cyclone year within this basin starts on 1 July and runs throughout the year, encompassing the tropical cyclone season, which runs from 1 November and lasts until 30 April each season. Within the basin, most tropical cyclones have their origins within the South Pacific convergence zone or within the Northern Australian monsoon trough, both of which form an extensive area of cloudiness and are dominant features of the season. Within this region a tropical disturbance is classified as a tropical cyclone when it has 10-minute sustained wind speeds of at least 65 km/h (40 mph) that wrap halfway around the low level circulation centre, while a severe tropical cyclone is classified when the maximum 10-minute sustained wind speeds are greater than 120 km/h (75 mph).
The 2001–02 Australian region cyclone season was a slightly below average tropical cyclone season. It officially started on 1 November 2001, and ended on 30 April 2002. However, the formation of Tropical Cyclone Alex on 26 October 2001 marked an earlier beginning to the season, and the season extended past the official end of the season when Tropical Cyclone Upia formed on 25 May 2002. The regional tropical cyclone operational plan also defines a "tropical cyclone year" separately from a "tropical cyclone season"; the "tropical cyclone year" began on 1 July 2001 and ended on 30 June 2002. The scope of the Australian region is limited to all areas south of the equator, east of 90°E and west of 160°E. This area includes Australia, Papua New Guinea, western parts of the Solomon Islands, East Timor and southern parts of Indonesia.
The 2008–09 Australian region cyclone season was a near average tropical cyclone season. It officially started on 1 November 2008, and officially ended on 30 April 2009. This season was also the first time that the BoM implemented a "tropical cyclone year." 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 2008 and ended on 30 June 2009.
The 1998–99 Australian region cyclone season was an above average tropical cyclone season that featured Gwenda, the most intense tropical cyclone in the Australian Region. It began on 1 November 1998 and ended on 30 April 1999. The regional tropical cyclone operational plan also defines a tropical cyclone year separately from a tropical cyclone season, which runs from 1 July 1998 to 30 June 1999.
The 1996–97 Australian region cyclone season was an above average tropical cyclone season. It ran from 1 November 1996 to 30 April 1997. The regional tropical cyclone operational plan also defines a tropical cyclone year separately from a tropical cyclone season, and the "tropical cyclone year" ran from 1 July 1996 to 30 June 1997.
The 2009–10 Australian region cyclone season was a below average tropical cyclone season, with eight tropical cyclones forming compared to an average of 12. The season began on 1 November 2009 and ran through until it end on 30 April 2010. The Australian region is defined as being to south of the equator, between the 90th meridian east and 160th meridian east. Tropical cyclones in this area are monitored by five Tropical Cyclone Warning Centres (TCWC's): Jakarta, Port Moresby, Perth, Darwin, and Brisbane, each of which have the power to name a tropical cyclone. The TCWC's in Perth, Darwin, and Brisbane are run by the Australian Bureau of Meteorology, who designate significant tropical lows with a number and the U suffix. The Joint Typhoon Warning Center also issues unofficial warnings for the region, designating significant tropical cyclones with the "S" suffix when they form west of 135°E, and the "P" suffix when they form east of 135°E.
The 2010–11 Australian region cyclone season was a near average tropical cyclone season, with eleven tropical cyclones forming compared to an average of 12. The season was also the costliest recorded in the Australian region basin, with a total of $3.62 billion in damages, mostly from the destructive Cyclone Yasi. The season began on 1 November 2010 and ended on 30 April 2011, although the first tropical cyclone formed on 28 October. The Australian region is defined as being to the south of the equator, between the 90th meridian east and 160th meridian east. Tropical cyclones in this area are monitored by five Tropical Cyclone Warning Centres (TCWC's): Jakarta, Port Moresby, Perth, Darwin, and Brisbane, each of which have the power to name a tropical cyclone. The TCWC's in Perth, Darwin, and Brisbane are run by the Bureau of Meteorology, who designate significant tropical lows with a number and the U suffix. The Joint Typhoon Warning Center also issues unofficial warnings for the region, designating significant tropical cyclones with the "S" suffix when they form west of 135°E, and the "P" suffix when they form east of 135°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 2014–15 Australian region cyclone season was a slightly below average tropical cyclone season. The season officially ran from 1 November 2014, to 30 April 2015, however, a tropical cyclone could form at any time between 1 July 2014, and 30 June 2015, and would count towards the season total. During the season, tropical cyclones were officially monitored, by one of the five Tropical Cyclone Warning Centres (TCWCs) that are operated in this region.
The 2015–16 Australian region cyclone season was the least active Australian region cyclone season since reliable records started during 1969, with only three named tropical cyclones developing in the region. Reasons for the low activity during the year included a positive Indian Ocean Dipole occurring and the 2014–16 El Niño event. Ahead of the season starting; the Australian Bureau of Meteorology predicted that there was a 91% chance that the season would be below average. As the 2015–16 tropical cyclone year opened on 1 July 2015, the newly named Tropical Cyclone Raquel moved south-westward into the Australian region. Over the next couple of days, the system meandered around 160°E and moved through the Solomon Islands, before it was last noted on 5 July. The basin subsequently remained quiet with only several weak tropical lows developing, before the first named tropical cyclone of the season was named Stan during 29 January 2016.
The 2017–18 Australian region cyclone season was an average period of tropical cyclone formation in the Southern Indian Ocean and South Pacific Ocean, between 90°E and 160°E, with 11 named storms, which 3 intensified into severe tropical cyclones. Another two tropical cyclones, Cempaka and Flamboyan occurred outside the Australian region but are included in the descriptions below. The season officially began 1 November 2017 and ended on 30 April 2018; however, tropical cyclones can form at any time of the year, as demonstrated by the first tropical low of the season in early August. Any tropical system that forms between 1 July 2017 and 30 June 2018 will count towards the season total. During the season, tropical cyclones will be officially monitored by one of the five tropical cyclone warning centres (TCWCs) that operate in this region. Three of the five centres are operated by the Australian Bureau of Meteorology (BOM) in Perth, Darwin and Brisbane, while the other two are operated by the National Weather Service of Papua New Guinea in Port Moresby and the Indonesian Agency for Meteorology, Climatology and Geophysics in Jakarta. The Joint Typhoon Warning Center (JTWC) of the United States and other national meteorological services, including Météo-France at Réunion, also monitored the basin during the season.
The 2018–19 Australian region cyclone season was an average season that saw the formation of 11 tropical cyclones, six of which intensified further to become severe tropical cyclones. The season officially began on 1 November 2018 and concluded on 30 April 2019; however, as evidenced by Tropical Low Liua in September 2018 and Tropical Cyclones Lili and Ann in May 2019, tropical cyclones can form at any time of the year. As such, any system existing between 1 July 2018 and 30 June 2019 would count towards the season total. During the season, tropical cyclones were officially monitored by the Bureau of Meteorology (BOM), the Indonesian Agency for Meteorology, Climatology and Geophysics (BMKG) in Jakarta, Indonesia, and the National Weather Service of Papua New Guinea in Port Moresby. The United States' Joint Typhoon Warning Center (JTWC) in Hawaii, and other national meteorological services such as MetService in New Zealand, Météo-France at La Réunion, and the Fiji Meteorological Service (FMS), also monitored parts of the basin during the season in an unofficial capacity.
Tropical Cyclone Cempaka was a tropical cyclone that impacted the island of Java and Bali, Indonesia in November 2017. Although it did not make landfall, Cempaka managed to cause 41 deaths, with more than 20,000 people evacuated and causing around US$83.6 million in damages. Cempaka was the fourth cyclone to be registered in Indonesia by the Tropical Cyclone Warning Center of the Indonesian Meteorology, Climatology, and Geophysical Agency (BMKG) since 2008 and the first since Cyclone Bakung in 2014. It also came closer to making landfall in that country than any other cyclone on record.
Tropical Cyclone Lili was a small and relatively weak off-season tropical cyclone that brought moderate impacts to the Maluku Islands and East Timor, and mild impacts to other parts of eastern Indonesia and far-northern Australia. It was the latest tropical cyclone to exist in the Australian Bureau of Meteorology's northern tropical cyclone region on record, surpassing Severe Tropical Cyclone Verna of 1977. Lili was the tenth tropical cyclone of the 2018–19 Australian region cyclone season, and the second of which to be named by the Indonesian Agency for Meteorology, Climatology and Geophysics. Lili originated from a tropical low that formed over the Banda Sea on 4 May 2019. The system gradually organised as it tracked slowly southwards, and strengthened into a Category 1 tropical cyclone on the Australian scale on 9 May. Lili reached peak intensity later that day, with ten-minute sustained winds of 75 km/h (47 mph) and a central barometric pressure of 997 hPa (29.44 inHg). The Joint Typhoon Warning Center estimated one-minute mean winds at this time to be at 100 km/h (62 mph). Weakening commenced soon thereafter, and the system fell below cyclone intensity on 10 May after turning to the west. Lili made landfall in northern East Timor the following day as a weak tropical low, and dissipated shortly afterwards.
The year 1992 featured the highest amount of accumulated cyclone energy (ACE) on record, with an ACE rating of 1,163.1 units. It would be regarded as one of the most intense tropical cyclone years on record. Throughout the year, 111 tropical cyclones formed, of which 101 were given names by various weather agencies. Five Category 5 tropical cyclones would form in 1992.
Indonesia is an island country in Southeast Asia and Oceania, located in the Pacific Ocean and the Indian Ocean. The largest island nation in the world, the country is the home of over seventeen thousand islands.
In 2024, tropical cyclones will form in seven major bodies of water, commonly known as tropical cyclone basins. Tropical cyclones will be named by various weather agencies when they attain maximum sustained winds of 35 knots.
