Tropical cyclone naming

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 (61 km/h; 38 mph), 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.

Before it became standard practice to give personal (first) names to tropical cyclones, they were named after places, objects, or the saints' feast days on which they occurred. Credit for the first usage of personal names for weather systems is generally given to Queensland Government meteorologist Clement Wragge, who named systems between 1887 and 1907. When Wragge retired, the practice fell into disuse for several years until it was revived in the latter part of World War II for the Western Pacific. Formal naming schemes and lists have subsequently been used for major storms in the Eastern, Central, Western and Southern Pacific basins, and the Australian region, Atlantic Ocean and Indian Ocean.

Before the formal start of naming, tropical cyclones were often named after places, objects, or saints' feast days on which they occurred. The credit for the first usage of personal names for weather systems is generally given to the Queensland Government meteorologist Clement Wragge, who named systems between 1887 and 1907. This system of naming weather systems subsequently fell into disuse for several years after Wragge retired until it was revived in the latter part of World War II for the Western Pacific. Formal naming schemes have subsequently been introduced for the North Atlantic, Eastern, Central, Western and Southern Pacific basins as well as the Australian region and Indian Ocean.

As of 2014^[update], tropical cyclones are officially named by one of eleven warning centers and retain their names throughout their lifetimes to facilitate the effective communication of forecasts and storm-related hazards to the general public. This is especially important when multiple storms are occurring simultaneously in the same ocean basin. Names are generally assigned in order from predetermined lists, once they produce one, three, or ten-minute sustained wind speeds of more than 65 km/h (40 mph). However, standards vary from basin to basin, with some systems named in the Western Pacific when they develop into tropical depressions or enter PAGASA's area of responsibility. Within the Southern Hemisphere, systems must be characterized by a significant amount of gale-force winds occurring around the center before they are named.

Any member of the World Meteorological Organization's hurricane, typhoon and tropical cyclone committees can request that the name of a tropical cyclone be retired or withdrawn from the various tropical cyclone naming lists. A name is retired or withdrawn if a consensus or majority of members agree that the system has acquired a special notoriety, such as causing a large number of deaths and amounts of damage, impact, or for other special reasons. A replacement name is then submitted to the committee concerned and voted upon, but these names can be rejected and replaced with another name for various reasons: these reasons include the spelling and pronunciation of the name, the similarity to the name of a recent tropical cyclone or on another list of names, and the length of the name for modern communication channels such as social media. PAGASA also retires the names of significant tropical cyclones when they have caused at least ₱1 billion (US$20.3 million) in damage or have caused at least 300 deaths.

Within the North Atlantic Basin, tropical or subtropical storms are named by the United States National Hurricane Center (NHC/RSMC Miami), when they are judged to have 1-minute sustained winds of at least 34 kn (39 mph; 63 km/h). The name selected comes from one of six rotating alphabetic lists of twenty-one names, that are maintained by the World Meteorological Organization's (WMO) RA IV Hurricane Committee. These lists skip the letters Q, U, X, Y and Z, rotate from year to year and alternate between male and female names. Should all of the names for a given year be used up, then any additional storms would be named using names from a supplemental list. The names of significant tropical cyclones are retired from the lists, with a replacement name selected at the next meeting of the Hurricane Committee.

Within the Eastern Pacific Ocean, there are two warning centers that assign names to tropical cyclones on behalf of the World Meteorological Organization when they are judged to have intensified into a tropical storm with winds of at least 34 kn (39 mph; 63 km/h). Tropical cyclones that intensify into tropical storms between the coast of Americas and 140°W are named by the National Hurricane Center (NHC/RSMC Miami), while tropical cyclones intensifying into tropical storms between 140°W and 180° are named by the Central Pacific Hurricane Center (CPHC/RSMC Honolulu). Significant tropical cyclones have their names retired from the lists and a replacement name selected at the next World Meteorological Organization Hurricane Committee.

When a tropical depression intensifies into a tropical storm to the north of the Equator between the coastline of the Americas and 140°W, it will be named by the NHC. There are six lists of names which rotate every six years and begin with the letters A—Z used, skipping Q and U, with each name alternating between a male or a female name. The names of significant tropical cyclones are retired from the lists, with a replacement name selected at the next meeting of the Hurricane Committee. If all of the names on the annual name list are used, any additional tropical or subtropical storms will receive a name from a supplemental list.