Hurricane (tropical cyclone)

Hurricane (tropical cyclone)
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Name	Hurricane (tropical cyclone)
Caption	Satellite image of a mature hurricane
Formation	Tropical cyclogenesis
Dissipation	Extratropical transition or landfall decay
Highest winds	Sustained winds
Lowest pressure	Central pressure
Areas affected	Tropical and subtropical regions

Hurricane (tropical cyclone) is a type of tropical cyclone characterized by a warm-core, rotating low-pressure center with sustained winds exceeding regional thresholds and organized convection. These systems affect tropical and subtropical oceans and can produce catastrophic wind, storm surge, and freshwater flooding across island nations, coastal cities, and inland river basins.

Definition and classification

A hurricane is defined by meteorological agencies such as the National Hurricane Center, Japan Meteorological Agency, Australian Bureau of Meteorology, Météo‑France, and the India Meteorological Department using criteria tied to sustained wind speeds, central pressure, and structural features; in the North Atlantic Ocean and Northeastern Pacific Ocean the Saffir–Simpson scale classifies hurricanes into categories 1–5. Regional nomenclature varies: in the Northwestern Pacific Ocean storms are termed typhoons by the Japan Meteorological Agency and Hong Kong Observatory, while the South Pacific and Indian Ocean use "tropical cyclone" with intensity scales by the Fiji Meteorological Service and Météo Madagascar. Agencies such as the World Meteorological Organization coordinate naming lists together with national meteorological services including the National Oceanic and Atmospheric Administration and Servicio Meteorológico Nacional.

Formation and meteorology

Tropical cyclogenesis commonly occurs over warm oceanic waters where thermodynamic and dynamic conditions converge, including sea surface temperatures above thresholds monitored by NOAA, sufficient low-level vorticity influenced by features like the Intertropical Convergence Zone, vertical wind shear regimes analyzed by the European Centre for Medium-Range Weather Forecasts and GFS, and mid-tropospheric humidity fields observed by satellites from NASA and EUMETSAT. Large-scale drivers such as the El Niño–Southern Oscillation, Madden–Julian Oscillation, Atlantic Multidecadal Oscillation, and variations in the North Atlantic Oscillation modulate seasonal activity. Tropical waves emerging from the West African coast and disturbances near the Monsoon trough can initiate development, which is then tracked by reconnaissance aircraft from the United States Air Force Reserve and NOAA Hurricane Hunters.

Structure and dynamics

A hurricane's core comprises the eye, eyewall, and rainbands, with the eyewall hosting the most intense convection and peak winds as documented in studies by Kerry Emanuel, William Gray, and research centers such as the Woods Hole Oceanographic Institution. The system's warm-core thermal structure contrasts with extratropical cyclones analyzed by Jacob Bjerknes, while processes like eyewall replacement cycles, vortex tilt, and stratosphere–troposphere exchange involve dynamics explored at institutions including MIT, Caltech, and Princeton University. Ocean–atmosphere interaction, including sea surface heat fluxes studied by Scripps Institution of Oceanography and upper-ocean mixing observed by Argo floats, governs intensity changes.

Impacts and hazards

Hurricanes generate multiple hazards: extreme winds that damage infrastructure in cities such as Miami, New Orleans, and Manila; storm surge that inundates deltas like the Gulf of Mexico and islands including Hispaniola and Puerto Rico; and heavy rainfall producing fluvial and flash flooding in basins such as the Mississippi River and Ganges River delta. Secondary hazards include tornado outbreaks affecting regions like Florida and Texas, coastal erosion impacting sites such as Cape Hatteras National Seashore, and public health crises documented after events like Hurricane Katrina and Hurricane Maria. Economic and social consequences have been analyzed by organizations including the World Bank, United Nations Office for Disaster Risk Reduction, and Federal Emergency Management Agency.

Forecasting and warning systems

Operational forecasting relies on numerical weather prediction from centers such as the European Centre for Medium-Range Weather Forecasts, NOAA, and the Japan Meteorological Agency, observational platforms including geostationary satellites from GOES and Himawari, scatterometer data from missions by European Space Agency and NASA, and in-situ dropsonde measurements from NOAA Hurricane Hunters. Warning dissemination involves national services like the National Hurricane Center, regional specialized meteorological centers designated by the World Meteorological Organization, and emergency management agencies including FEMA, Red Cross, and national governments such as those of Bahamas, Philippines, and Japan issuing evacuation orders and public advisories.

Historical notable hurricanes

Notable historical storms include Hurricane Katrina (2005), Hurricane Maria (2017), Hurricane Harvey (2017), Hurricane Sandy (2012), Hurricane Andrew (1992), Labor Day hurricane (1935), Hurricane Wilma (2005), Hurricane Mitch (1998), and Hurricane Irma (2017); each event shaped policy in jurisdictions such as Louisiana, Puerto Rico, Texas, and Florida and spurred scientific inquiry at institutions including Columbia University and University of Miami. Historic analyses reference records from the International Best Track Archive for Climate Stewardship and paleotempestology investigations in regions like New England and the Yucatán Peninsula.

Mitigation, preparedness, and recovery

Mitigation and preparedness strategies span structural measures—coastal defenses in locations such as Netherlands and barrier systems studied by US Army Corps of Engineers—and nonstructural policies including zoning reforms implemented in Florida and building codes in Japan. Early warning systems coordinated by WMO and humanitarian response led by United Nations Office for the Coordination of Humanitarian Affairs and International Federation of Red Cross and Red Crescent Societies support evacuation, sheltering, and post-disaster recovery financed by entities like the World Bank and USAID. Community resilience initiatives in municipalities such as New Orleans and nations like Bahamas emphasize ecosystem-based approaches including mangrove restoration promoted by IUCN, insurance instruments like those from the Caribbean Catastrophe Risk Insurance Facility, and climate adaptation frameworks under UNFCCC agreements.

Category:Tropical cyclones