Tropical cyclones in 2004

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. 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 (seven basins combined), as calculated by Colorado State University was 1024.4 units.

The costliest tropical cyclone was Hurricane Ivan, which struck Caribbean and United States in September causing a tornado outbreak, with US$26.1 billion in damage. The deadliest tropical cyclone of the year was Hurricane Jeanne who killed for at least 3,006 deaths in Haiti.

Global atmospheric and hydrological conditions
Due to a Modoki El Niño – a rare type of El Niño in which unfavorable conditions are produced over the eastern Pacific instead of the Atlantic basin due to warmer sea surface temperatures farther west along the equatorial Pacific – activity was above average in North Atlantic Ocean.

North Atlantic Ocean
It was an above average season in which 16 tropical cyclones formed. All but one tropical depression attained tropical storm status, and nine of these became hurricanes. Six hurricanes further intensified into major hurricanes.

Systems
A total of 138 systems formed globally in the year with 60 of them causing significant damage, deaths, and/or setting records for their basin.

January


7 storms formed on January, in the Australian and Southwestern Indian basin, respectively. Cyclone Frank was the strongest.

February
5 systems formed on February. 3 on Australian region, 1 on South Pacific basin, and 1 on the Western Pacific. Tropical Cyclone Ivy is the strongest.

March
Average storms forming 12 storms. Strongest storm is Cyclone Gafilo with 895 hpa, Hurricane Catarina was the record breaking and the only hurricane in the South Atlantic.

April
Below average forming 9 systems. Only Typhoon Sudal (2004) became a storm, mostly being a depression.

May


8 systems formed on May. Typhoon Nida is the strongest.

June


7 storms formed on June. Typhoon Dianmu is the strongest.