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.
Tropical cyclone warnings and watches are alerts issued by national weather forecasting bodies to coastal areas threatened by the imminent approach of a tropical cyclone of tropical storm or hurricane intensity. They are notices to the local population and civil authorities to make appropriate preparation for the cyclone, including evacuation of vulnerable areas where necessary. It is important that interests throughout the area of an alert make preparations to protect life and property, and do not disregard it on the strength of the detailed forecast track.
A Pacific hurricane is a tropical cyclone that develops within the northeastern and central Pacific Ocean to the east of 180°W, north of the equator. For tropical cyclone warning purposes, the northern Pacific is divided into three regions: the eastern, central, and western, while the southern Pacific is divided into 2 sections, the Australian region and the southern Pacific basin between 160°E and 120°W. Identical phenomena in the western north Pacific are called typhoons. This separation between the two basins has a practical convenience, however, as tropical cyclones rarely form in the central north Pacific due to high vertical wind shear, and few cross the dateline.
Tropical cyclones are ranked on one of five tropical cyclone intensity scales, according to their maximum sustained winds and which tropical cyclone basins they are located in. Only a few scales of classifications are used officially by the meteorological agencies monitoring the tropical cyclones, but other scales also exist, such as accumulated cyclone energy, the Power Dissipation Index, the Integrated Kinetic Energy Index, and the Hurricane Severity Index.
Traditionally, areas of tropical cyclone formation are divided into seven basins. These include the north Atlantic Ocean, the eastern and western parts of the northern Pacific Ocean, the southwestern Pacific, the southwestern and southeastern Indian Oceans, and the northern Indian Ocean. The western Pacific is the most active and the north Indian the least active. An average of 86 tropical cyclones of tropical storm intensity form annually worldwide, with 47 reaching hurricane/typhoon strength, and 20 becoming intense tropical cyclones, super typhoons, or major hurricanes.
The 1997–98 Australian region cyclone season was a slightly below average tropical cyclone season. It ran from 1 November 1997 to 30 April 1998. 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 1997 to 30 June 1998.
During 2010, tropical cyclones formed within seven different tropical cyclone basins, located within various parts of the Atlantic, Pacific and Indian Oceans. During the year, a total of 111 tropical cyclones developed, with 64 of them being named by either a Regional Specialized Meteorological Center (RSMC) or a Tropical Cyclone Warning Center (TCWC). The most active basin was the North Atlantic, which documented 19 named systems, while the North Indian Ocean, despite only amounting to five named systems, was its basin's most active since 1998. Conversely, both the West Pacific typhoon and East Pacific hurricane seasons experienced the fewest cyclones reaching tropical storm intensity in recorded history, numbering 14 and 8, respectively. Activity across the southern hemisphere's three basins—South-West Indian, Australian, and South Pacific—was spread evenly, with each region recording 7 named storms apiece. The southern hemisphere's strongest tropical cyclone was Cyclone Edzani, which bottomed out with a barometric pressure of 910 mbar in the South-West Indian Ocean. Nineteen Category 3 tropical cyclones formed, including four Category 5 tropical cyclones in the year. The accumulated cyclone energy (ACE) index for the 2010, as calculated by Colorado State University was 573.8 units.
Throughout 2006, 133 tropical cyclones formed in seven bodies of water known as tropical cyclone basins. Of these, 80 have been named, including two tropical cyclones in the South Atlantic Ocean, and a tropical cyclone in the Mediterranean Sea, by various weather agencies when they attained maximum sustained winds of 65 km/h (40 mph). The strongest storms of the year were Typhoon Yagi in the Western Pacific, and Cyclone Glenda of the Australian region. The deadliest and costliest storms of the year were a series of five typhoons that struck the Philippines and China; Chanchu, Bilis, Saomai, Xangsane, and Durian, with most of the damage being caused by Durian of November. So far, 27 Category 3 tropical cyclones formed, including five Category 5 tropical cyclones in the year. The accumulated cyclone energy (ACE) index for the 2006, as calculated by Colorado State University was 761 units.
The 2019–20 Australian region cyclone season was a below average tropical cyclone season for the waters surrounding Australia between longitudes 90°E and 160°E. The season officially began on 1 November 2019 and ended on 30 April 2020; however, tropical cyclones can form at any time of year, as evidenced by Tropical Cyclone Mangga during May 2020. As such, any system existing between 1 July 2019 and 30 June 2020 would count towards the season total. The season featured the region's second-latest start on record, with the formation of the first tropical low only occurring on 4 January 2020. A total of eight tropical cyclones formed during the season, which represents the region's least active season since the 2016–17 season. Three systems intensified further into severe tropical cyclones, and three systems made landfall within the region at tropical cyclone intensity. A total of 28 fatalities were caused, either directly or indirectly, as a result of impacts from the season's systems. Cyclone Ferdinand was the strongest of the season reaching Category 4 in late February 2020. However, it was the second-strongest storm, Cyclone Damien, that was the most damaging. Damien was the strongest tropical cyclone to strike Western Australia's Pilbara Region since Cyclone Christine in 2013, making landfall directly over the town of Dampier.
The following is a list of tropical cyclones by year. Since the year 957, there have been at least 12,791 recorded tropical or subtropical cyclones in the Atlantic, Pacific, and Indian Oceans, which are known as basins. Collectively, tropical cyclones caused more than US$1.2 trillion in damage, unadjusted for inflation, and have killed more than 2.6 million people. Most of these deaths were caused by a few deadly cyclones, including the 1737 Calcutta cyclone, the 1839 Coringa cyclone, the 1931 Shanghai typhoon, the 1970 Bhola cyclone, Typhoon Nina in 1975, the 1991 Bangladesh cyclone, and Cyclone Nargis in 2008.
During 2015, tropical cyclones formed in seven major bodies of water, commonly known as tropical cyclone basins. Tropical cyclones will be assigned names by various weather agencies if they attain maximum sustained winds of 35 knots. During the year, one hundred thirty-four systems have formed and ninety-two were named. The most intense storm of the year was Hurricane Patricia, with maximum 1-minute sustained wind speeds of 345 km/h (215 mph) and a minimum pressure of 872 hPa (25.75 inHg). The deadliest tropical cyclone was Cyclone Komen, which caused 280 fatalities in Southeast India and Bangladesh, while the costliest was Typhoon Mujigae, which caused an estimated $4.25 billion USD in damage after striking China. Forty Category 3 tropical cyclones formed, including nine Category 5 tropical cyclones in the year. The accumulated cyclone energy (ACE) index for the 2015, as calculated by Colorado State University (CSU) was 1047 units.
During 2019, tropical cyclones formed within seven different tropical cyclone basins, located within various parts of the Atlantic, Pacific and Indian Oceans. During the year,a total of 142 systems formed, with 100 of these developing further and being named by the responsible warning centre. The strongest tropical cyclone of the year was Typhoon Halong, with a minimum barometric pressure of 905 hPa (26.72 inHg). Cyclone Idai became the deadliest tropical cyclone of the year, after killing at least 1,303 people in Mozambique, Malawi, Zimbabwe, and Madagascar. The costliest tropical cyclone of the year was Typhoon Hagibis, which caused more than $15 billion in damage after striking Japan.
During 2004, tropical cyclones formed within seven different tropical cyclone basins, located within various parts of the Atlantic, Pacific and Indian Oceans. During the year, a total of 132 systems formed with 82 of these developing further and were named by the responsible warning centre. The strongest tropical cyclone of the year was Cyclone Gafilo, which was estimated to have a minimum barometric pressure of 895 hPa (26.43 inHg). The most active basin in the year was the Western Pacific, which documented 29 named systems, while the North Atlantic 15 named systems formed. Conversely, both the Eastern Pacific hurricane and North Indian Ocean cyclone seasons experienced a below average number of named systems, numbering 12 and 4, respectively. Activity across the southern hemisphere's three basins—South-West Indian, Australian, and South Pacific—was spread evenly, with each region recording seven named storms apiece. Throughout the year, 28 Category 3 tropical cyclones formed, including seven Category 5 tropical cyclones formed in the year. The accumulated cyclone energy (ACE) index for the 2004, as calculated by Colorado State University was 1024.4 units.
The year 1997 was regarded as one of the most intense tropical cyclone years on record, featuring a record 12 category 5-equivalent tropical cyclones, according to the Saffir–Simpson hurricane wind scale. The year also featured the second-highest amount of accumulated cyclone energy (ACE) on record, just behind 1992 and 2018. Throughout the year, 108 tropical cyclones have developed in bodies of water, commonly known as tropical cyclone basins. However, only 89 tropical cyclones were of those attaining 39 mph or greater, falling just below the long term average of 102 named systems. The most active basin was the Western Pacific, attaining an ACE amount of 571, the highest ever recorded in any season in any basin on record. The deadliest tropical cyclone was Severe Tropical Storm Linda (Openg). The costliest tropical cyclone was Super Typhoon Winnie (Ibiang), which set a record for having the largest eye on record. The most intense tropical cyclone was Hurricane Linda, peaking at 902 hPa/mbar. Typhoon Paka (Rubing), the longest-lived system, produced the fourth-highest ACE for a single tropical cyclone, just behind Typhoon Nancy (1961), Hurricane/Typhoon Ioke (2006), and Cyclone Freddy (2023). The accumulated cyclone energy (ACE) index for the 1997, as calculated by Colorado State University was 1,099.2 units.
During 1999, tropical cyclones formed within seven different bodies of water called basins. To date, 142 tropical cyclones formed in bodies of water known as tropical cyclone basins, of which 72 were given names by various weather agencies. The strongest tropical cyclone of the year was Gwenda, attaining maximum sustained winds of 120 knots and a pressure of 900 hPa (26.58 inHg), later tied with Inigo in 2003. Floyd was the costliest tropical cyclone of the year, with around $6.5 billion worth of damages as it affected the Bahamas, the East Coast of the United States, and the Atlantic Canada. The deadliest cyclone of this year was the 1999 Odisha cyclone, which was blamed for over 9,667 deaths as it devastated India. It was also the strongest Northern Hemisphere cyclone of the year with the pressure of 912 hPa (26.93 inHg) and third most intense tropical cyclone worldwide next to Cyclone Gwenda and Cyclone Vance. Three Category 5 tropical cyclones were formed in 1999. The accumulated cyclone energy (ACE) index for the 1999, as calculated by Colorado State University was 606.4 units.
During 1998, tropical cyclones formed within seven different tropical cyclone basins, located within various parts of the Atlantic, Pacific, and Indian Oceans. A total of 125 tropical cyclones formed, with 72 of them being named by various weather agencies when they attained maximum sustained winds of 35 knots. The strongest tropical cyclones were Zeb, Ron and Susan which peaked with a pressure of 900 hPa (26.58 inHg). Hurricane Mitch of late October was the deadliest tropical cyclone, killing 11,000 people as it catastrophically affected Central America, and Mexico as a Category 5 major hurricane. Meanwhile, Georges became the costliest, with the damages amounting to $9.37 billion, which also became the costliest in the history of the Dominican Republic and the country of Saint Kitts and Nevis. Throughout the year, four Category 5 tropical cyclones formed. The accumulated cyclone energy (ACE) index for the 1998, as calculated by Colorado State University was 773.1 units.
During 1996, tropical cyclones formed within seven different tropical cyclone basins, located within various parts of the Atlantic, Pacific, and Indian Oceans. During the year, a total of 139 tropical cyclones formed in bodies of water known as tropical cyclone basins. 90 of them were named by various weather agencies when they attained maximum sustained windS of 35 knots. The strongest tropical cyclone of the year was Cyclone Daniella, peaking with a pressure of 915 hPa (27.02 inHg) in the open waters of the Indian Ocean. Hurricane Fran and Typhoon Herb tie for the costliest storm of the year, both with a damage cost of $5 billion. The deadliest tropical cyclone of the year was the 1996 Andhra Pradesh cyclone, which was blamed for over 1,000 fatalities as it directly affected the state of Andhra Pradesh in India. Five Category 5 tropical cyclones were formed in 1996. The accumulated cyclone energy (ACE) index for the 1996, as calculated by Colorado State University was 960 units.
During 1991, tropical cyclones formed within seven different tropical cyclone basins, located within various parts of the Atlantic, Pacific and Indian Oceans. During the year, a total of 100 systems formed with 75 of these developing further and were named by the responsible warning centre. The strongest tropical cyclone of the year was Typhoon Yuri, which was estimated to have a minimum barometric pressure of 895 hPa (26.43 inHg). The deadliest tropical cyclone was Cyclone BOB 01, which caused 138,866 fatalities in Bangladesh, Northeastern India, Myanmar, Yunnan, while the costliest was Typhoon Mireille, which caused an estimated $10 billion USD in damage after striking Japan. Four Category 5 tropical cyclones formed in 1991.
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. So far, twenty-four systems have formed, with fourteen of them being named. The most intense storm of the year so far is Djoungou, with a minimum pressure of 922 hPa (27.23 inHg). Among this year's systems, so far, five have intensified into major tropical cyclones, with no tropical cyclones intensifying into Category 5 tropical cyclones on the Saffir–Simpson scale (SSHWS). The accumulated cyclone energy (ACE) index for the 2024 so far, as calculated by Colorado State University (CSU), is 98.7 units overall.
During 2023, tropical cyclones formed in seven major bodies of water, commonly known as tropical cyclone basins. They were named by various weather agencies when they attained maximum sustained winds of 35 knots. Throughout the year, a total of 115 systems formed, with 79 of them being named. The most intense storm this year was Typhoon Mawar, which had a minimum pressure of 900 hPa (26.58 inHg). The deadliest tropical cyclone of the year was Storm Daniel, which killed at least 10,028 people in Libya, Greece, Turkey, and Bulgaria. Meanwhile, the costliest tropical cyclone was Typhoon Doksuri which caused at least US$28.4 billion worth of damage in China, the Philippines and Taiwan, becoming the costliest on record outside the Atlantic Ocean basin. Among this year's systems, thirty became major tropical cyclones, of which nine intensified into Category 5 tropical cyclones on the Saffir–Simpson scale (SSHWS). This year, for the first time on record, at least one such Category 5 system formed in each tropical cyclone basin: Typhoons Mawar and Bolaven in the western Pacific Ocean, Hurricanes Jova and Otis in the eastern Pacific, Hurricane Lee in the Atlantic, Cyclone Mocha in the North Indian Ocean, Cyclone Freddy in the southwest Indian Ocean, Cyclone Ilsa in the Australian region, and Cyclone Kevin in the South Pacific. The accumulated cyclone energy (ACE) index for the 2023, as calculated by Colorado State University (CSU) was 857.4 units, which was above the 1991-2020 mean of 770.2 units.
