On the Eastern and Central Pacific, three simultaneous tropical cyclones existed on September 22. Jova, Kenneth and Max
During 2005, 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 141 systems formed with 94 of these developing further and were named by the responsible warning centre. The strongest tropical cyclone of the year was Hurricane Wilma, which was estimated to have a minimum barometric pressure of 882 hPa (26.05 inHg).
The 2005 was above-average in terms of the number of storms. The most active basin in the year was the North Atlantic, which documented 28 named systems. The Western Pacific had an near-average season with 23 named storms. The Eastern Pacific hurricane season experienced an above average number of tropical storm intensity systems, numbering 15. Activity across the southern hemisphere's three basins - South-West Indian, Australian, and South Pacific - was fairly significant, with the regions recording 23 named storms altogether, with the most intense Southern Hemisphere cyclone of the year, Cyclone Percy from the South Pacific Ocean basin peaking at 145 mph (230 km/h) and 900 millibars.
The deadliest and costliest tropical cyclone of the year was Hurricane Katrina in the North Atlantic Ocean, which killed at least 1,800 people in New Orleans and the surrounding areas; Katrina caused more than $125 billion in damage after striking United States, the costliest tropical cyclone on record, tying with Hurricane Harvey in 2017.
Global atmospheric and hydrological conditions
North Atlantic Ocean
The activity was the most active Atlantic hurricane season in recorded history, shattering numerous records, with 31 tropical or subtropical cyclones recorded. The United States National Hurricane Center[nb 1]named 27 storms, exhausting the annual pre-designated list and resulting in the usage of six Greek letter names. A record 15 storms attained hurricane status, with maximum sustained winds of at least 74 mph (119 km/h); of those, a record seven became major hurricanes, which are a Category 3 or higher on the Saffir-Simpson scale. The season's impact was widespread and catastrophic. Its storms caused an estimated 3,912 deaths and approximately $171.7 billion in damage. It was the costliest season on record at the time, until its record was surpassed 12 years later. It also produced the second-highest accumulated cyclone energy (ACE) in the Atlantic basin, surpassed only by the 1933 season. The season officially began on June 1, 2005, and the first storm – Arlene – developed on June 8. Hurricane Dennis in July inflicted heavy damage to Cuba. Hurricane Stan in October was part of a broader weather system that killed 1,668 people and caused $3.96 billion in damage to eastern Mexico and Central America, with Guatemala hit the hardest. The final storm – Zeta – formed in late December and lasted until January 6, 2006.
Eastern Pacific Ocean
The activity continued the trend of generally below-average activity that began a decade prior. The season's first tropical cyclone, Adrian, developed on May 17 and reached its peak as a Category 1 hurricane. Named storms are infrequent in May, with one tropical storm every two years and a hurricane once every four years.[2] At the time, Adrian was the fourth earliest tropical cyclone to form in the eastern Pacific since reliable record-keeping began in 1971. Activity throughout the remainder of the season was far less notable, with 16 tropical cyclones, 15 named storms, 7 hurricanes, and 2 major hurricanes. The long-term 1971–2004 average suggests an average season to feature 15 named storms, 9 hurricanes, and 4 major hurricanes. October in particular was notably quiet, with the formation of only one tropical depression; only three other seasons, 1989, 1995, and 1996, ended the month without the designation of a named storm.[3]
^The sum of the number of systems and fatalities in each basin will not equal the number shown as the total. This is because when systems move between basins, it creates a discrepancy in the actual number of systems and fatalities.
1 Only systems that formed either on or after January 1, 2005 are counted in the seasonal totals. 2 Only systems that formed either before or on December 31, 2005 are counted in the seasonal totals. 3 The wind speeds for this tropical cyclone/basin are based on the IMD Scale which uses 3-minute sustained winds.
4 The wind speeds for this tropical cyclone/basin are based on the Saffir Simpson Scale which uses 1-minute sustained winds. 5The wind speeds for this tropical cyclone are based on Météo-France which uses gust winds.
^Richard D. Knabb; James L. Franklin (June 1, 2005). Monthly Tropical Weather Summary: May (Report). Miami, Florida: National Hurricane Center. Retrieved April 25, 2017.
^Stacy R. Stewart; John L. Beven II; James L. Franklin (November 1, 2005). Monthly Tropical Weather Summary: October (Report). National Hurricane Center. Retrieved April 27, 2017.