During 2002, tropical cyclones formed within seven different tropical cyclone basins, located within various parts of the Atlantic, Pacific and Indian Oceans. Throughout the year, a total of 123 tropical cyclones formed, of which 80 tropical cyclones developed enough to be named by either a Regional Specialized Meteorological Center (RSMC) or a Tropical Cyclone Warning Center (TCWC). The strongest system was Cyclone Zoe, with a barometric pressure of . The costliest and deadliest tropical cyclone of the year was Typhoon Rusa, killing 238 in South Korea and causing $4.2 billion (2002 USD) in damages. 26 Category 3 tropical cyclones, including eight Category 5 tropical cyclones formed in 2002. The accumulated cyclone energy (ACE) index for 2002 (seven basins combined), as calculated by Colorado State University was 812 units.
Tropical cyclone activity in each basin is under the authority of an RSMC. The National Hurricane Center (NHC) is responsible for tropical cyclones in the North Atlantic and East Pacific. The Central Pacific Hurricane Center (CPHC) is responsible for tropical cyclones in the Central Pacific. Both the NHC and CPHC are subdivisions of the National Weather Service. Activity in the West Pacific is monitored by the Japan Meteorological Agency (JMA). Systems in the North Indian Ocean are monitored by the India Meteorological Department (IMD). The Météo-France located in Réunion (MFR) monitors tropical activity in the South-West Indian Ocean. The Australian region is monitored by five TCWCs that are under the coordination of the Australian Bureau of Meteorology (BOM). Similarly, the South Pacific is monitored by both the Fiji Meteorological Service (FMS) and the Meteorological Service of New Zealand Limited. Other, unofficial agencies that provide additional guidance in tropical cyclone monitoring include the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) and the Joint Typhoon Warning Center (JTWC).
Global atmospheric and hydrological conditions
In the seven basins, there are a variety of different factors that impact tropical cyclogenesis. One of the most important factors is the presence or lack of El Niño–Southern Oscillation, which was present for much of the second half of 2002. El Niño is caused by the weakening of trade winds. This leads to the formation of a band of warm ocean water in the equatorial Eastern Pacific basin, marked by a reduction in upwelling.
The El Niño phenomenon has global effects on cyclone formation, development, and tracks. In the Atlantic Ocean, El Niño years see less active hurricane seasons due to stronger westerly winds, which cause increased vertical wind shear, inhibiting cyclonic development. By contrast, the Eastern Pacific basin exhibits lower wind shear and higher sea surface temperatures, leading to more active cyclone seasons. In the Western Pacific, tropical cyclone formation shifts eastward, without a major change in activity; thus, a typhoon that would normally affect China might shift to instead impact Micronesia. In the Southern Hemisphere, the situation in the Northern Hemisphere is mirrored: the Australian region sees fewer cyclones, while the South Pacific becomes more active. All these factors were present in 2002: the Atlantic hurricane season was slightly below-average, the Eastern Pacific had an unusually high number of major hurricanes, the Western Pacific saw a dearth of activity in the South China Sea in conjunction with an abnormally strong subtropical ridge, and the Australian region saw no storms in the second half of 2002, while the South Pacific season was one of the most intense on record.
Summary
North Atlantic Ocean
The 2002 season was near-normal in activity, with twelve tropical storms forming, but had a below-average amount of more intense storms, with only four hurricanes and two major hurricanes. A more accurate picture of the season's activity is its accumulated cyclone energy (ACE), which gives higher weight to more intense tropical cyclones and longer-lived tropical cyclones – thus, a season with many weak and short-lived storms will have a lower ACE, while a season with a few long-lived intense hurricanes will have a higher ACE despite superficially appearing to be a less active season. The ACE for the 2002 season was 65.1, only three-fourths of the long-term average of 87.5, classifying the 2002 season as slightly below-average.
The season had a rather late start, with the first storm, Arthur, forming on 14 July, causing one death in the American Southeast. Arthur was followed by five more tropical storms over the next two months, of which several caused significant damage, most notably Tropical Storm Fay, which made landfall in Texas on 7 August, causing in damage. Tropical Storms Bertha and Cristobal also caused minor damage and deaths, to the Gulf Coast and Eastern Seaboard, respectively. On 8 September, Subtropical Storm Gustav formed between the Bahamas and Bermuda, becoming the first-ever Atlantic subtropical cyclone to receive a name from the regular naming list. Three days later, Gustav intensified into a hurricane, becoming the latest first hurricane of the season since 1941. The hurricane would later affect land, causing several hundreds of thousands of dollars of damage along the East Coast. A few days later, Tropical Storm Hanna formed, which would soon make landfall in and cause in damage to the Gulf Coast.
On 14 September, a depression formed near Trinidad and Tobago, then degenerated into a tropical wave the next day. As the tropical wave moved west over the next few days, it reorganized as a tropical depression, intensifying into Tropical Storm Isidore on 18 September. The next day, Isidore intensified into a hurricane, making landfall in western Cuba on 20 September before turning west and making landfall on the northern coast of the Yucatán Peninsula as a Category 3 hurricane the next day. After the landfall, the storm turned north, hitting Louisiana as a tropical storm on 26 September before dissipating. Isidore was the most destructive storm of the season, causing and killing 22 people, mostly in the Yucatán Peninsula. The next storm to affect land was Hurricane Lili, which formed on 21 September east of the Lesser Antilles. After intensifying into a tropical storm, Lili degenerated into a tropical wave, reforming as a tropical storm southeast of Jamaica on 26 September. Lili became a hurricane near the Cayman Islands and made landfall in western Cuba on 1 October at Category 2 intensity. Moving northwest, the storm intensified into a Category 4 hurricane, reaching its peak intensity of , the highest wind speed of any Atlantic hurricane in 2002. Lili weakened to a Category 1 hurricane, making landfall in Louisiana on 3 October before dissipating the next day. With in damage and 15 deaths to Louisiana and the Caribbean Islands, Lili was the second-costliest and second-deadliest Atlantic hurricane of 2002. About a week after Lili dissipated, the long-lived Hurricane Kyle, which had formed on 20 September, approached the Carolinas as a tropical storm. Kyle made two separate landfalls on 11 October, one in South Carolina and one in North Carolina, causing in damage before becoming extratropical the next day. Its remnants caused one death in Britain. Lasting twenty-two days, Kyle was the longest-lived tropical cyclone of 2002 and the fourth-longest-lived Atlantic hurricane ever.
The 2002 season was an anomaly, setting records for both activity and inactivity. It broke the record for the most active September, with eight named storms forming, tied in 2007 and 2010 and broken in 2020. However, the length of the season – the amount of time from the first storm to the last storm – was only three months, the shortest since 1983. There was also an unusual lack of storms forming from tropical waves. Usually the most common source of tropical cyclogenesis, only Dolly, Isidore, and Lili formed this way, with the other storms forming from subtropical or non-tropical systems. This abnormal activity was caused by a moderate El Niño, which allowed high wind shear to exist across the Atlantic except in September, when the El Niño temporarily weakened and wind shear decreased. Wind shear was especially high in areas with high tropical wave formation levels, such as the Caribbean Sea.
Eastern Pacific Ocean
The season was slightly above average as it saw three tropical cyclones reach Category 5 intensity on the Saffir–Simpson scale, tied for the most in a season with 1994 and 2018. The strongest storm this year was Hurricane Kenna, which reached Category 5 on the Saffir–Simpson scale. It made landfall near Puerto Vallarta, located in the Mexican state of Jalisco, on October 25. Elsewhere, Tropical Storm Julio made landfall in Mexico, and Tropical Storm Boris dumped torrential rain along the Mexican coast, despite remaining offshore.
Other storms were individually unusual. Hurricanes Elida and Hernan also reached Category 5 intensity, but neither caused any damage. Hurricane Fausto had no effect on land, but it regenerated into a weak tropical storm at an abnormally high latitude.
Western Pacific Ocean
The season was slightly above average with many tropical cyclones affecting Japan and China. Every month had tropical activity, with most storms forming from July through October. Overall, there were 44 tropical depressions declared officially or unofficially, of which 26 became named storms; of those, there were 15 typhoons, which is the equivalent of a minimal hurricane, while 8 of the 15 typhoon intensified into super typhoons unofficially by the JTWC. The season began early with the first storm, Tapah, developing on January 10, east of the Philippines. Two months later, Typhoon Mitag became the first super typhoon ever to be recorded in March. In June, Typhoon Chataan dropped heavy rainfall in the Federated States of Micronesia, killing 48 people and becoming the deadliest natural disaster in the state of Chuuk. Chataan later left heavy damage in Guam before striking Japan. In August, Typhoon Rusa became the deadliest typhoon in South Korea in 43 years, causing 238 deaths and $4.2 billion in damage. Typhoon Higos in October was the fifth strongest typhoon to strike Tokyo since World War II. The final typhoon of the season was Typhoon Pongsona, which was one of the costliest storms on record in Guam; it did damage worth $700 million on the island before dissipating on December 11.
The season began early, but did not become active until June, when six storms passed near or over Japan after a ridge weakened. Nine storms developed in July, many of which influenced the monsoon trough over the Philippines to produce heavy rainfall and deadly flooding. The flooding was worst in Luzon, where 85 people were killed. The series of storms caused the widespread closure of schools and offices. Many roads were damaged, and the floods left about $1.8 million (₱94.2 million PHP) in crop damage, largely to rice and corn. Overall damage from the series of storms was estimated at $10.3 million (₱522 million PHP). From June to September, heavy rainfall affected large portions of China, resulting in devastating flooding that killed over 1,500 people and left $8.2 billion (¥68 billion CNY) in damage. During this time, Tropical Storm Kammuri struck southern China with a large area of rainfall that damaged or destroyed 245,000 houses. There were 153 deaths related to the storm, mostly inland in Hunan, and damage totaled $322 million (¥2.665 billion CNY). Activity shifted farther to the east after September, with Typhoon Higos striking Japan in October and Typhoon Pongsona hitting Guam in December.