Where Do Tropical Cyclone Names Come From?
Have you ever wondered why tropical cyclones are given names and how various parts of the world go about naming their tropical systems? Because of their long-term persistence, both tropical and subtropical cyclones are given names as a way to tell them apart when issuing forecasts and warnings. In YourWeatherBlog today, find out the similarities and differences between named storms in the Atlantic vs. the Pacific.
North Atlantic Ocean/Gulf of Mexico
The National Hurricane Center in Miami names tropical systems that develop in the North Atlantic Ocean and Gulf of Mexico. Since 1979 there have been six lists of names in use that consists of both male and female names. The names are in alphabetical order and after six years they are recycled, although the names of notable hurricanes, and in one case with 2001’s Tropical Storm Allison, have been retired by the World Meteorological Organization (WMO) on request.
List of names for the Atlantic hurricane season. Image: Wikipedia
If you remember back in 2005 all the names were used off the list. When this happens storms are then named after the letters of the Greek alphabet. Unlike the names that come from the list, Greek names are not retired. The 2005 hurricane season was the first time the Greek alphabet was used with 28 total storms (27 named storms and one unnamed).
The Pacific Ocean is broken down into three different regions. In the Eastern Pacific Ocean tropical cyclones that have tropical storm winds of at least 40 mph have two Regional Specialized Meteorological Center’s (RSMC’s) that name the storms depending on their location. Tropical cyclones that intensify into tropical storms between the coast of the Americas and 140°W are named by the National Hurricane Center in Miami, while tropical cyclones intensifying into tropical storms between 140°W and 180°W are named by the Central Pacific Hurricane Center in Honolulu, Hawaii.
In the North Pacific east of 140ºW, six lists of names are rotated on yearly bases and are maintained by the WMO. If all the names on the list are used, storms are then named after the letters of the Greek alphabet just like in the Atlantic.
List of North Pacific storm names east of 140ºW. Image: Wikipedia
In the Central North Pacific (140ºW to 180ºW), there are four lists that are used and maintained by the WMO. Unlike the previous regions I’ve mentioned, this list actually picks up where it leaves off the previous season. For example, if Lala was the last name to be used last year (see highlighted area), the first name this year would be Moke.
List of Central North Pacific storm names. Image: Wikipedia
In the regions just mentioned in the Pacific Ocean, tropical cyclones with winds 74 mph or higher are known as hurricanes. In the Northern Pacific west of 180º, they are known as typhoons.
In the Western Pacific Ocean (180ºE-100Eº) there are two separate agencies that assign names to tropical cyclones which often results in a cyclone having two names. The Japan Meteorological Agency names tropical cyclones if they have 10-minute sustained wind speeds of 65 km/h (40 mph) to the north of the equator between the 180°E and 100°E. While the Philippine Atmospheric, Geophysical and Astronomical Services Administration assigns names to tropical cyclones which move into or form as a tropical depression in their area of responsibility located between 135°E and 115°E and between 5°E-25°E even if the cyclone has had a name assigned to it by the Japan Meteorological Agency. This of course leads to the system having two names.
Tropical cyclones are named from this list (see below) once they reach tropical storm strength. Each of the 14 nations or territories in the area submitted 10 names. The two most recent storms which come from list four, are Typhoon Conson and Tropical Storm Chanthu (see highlighted area), both of which made landfall into southern China less than a week apart.
List of named storms for the Western Pacific. Image:Wikipedia
Tropical Storm Chanthu. Image: Joint Typhoon Warning Center
No matter what part of the world you live in, each region has its own unique way of naming tropical cyclones. Did you know in 1953 the U.S. started using solely female names for storms? Originally, using women’s names became the practice during World War II. Then in 1951 the U.S. started naming storms using the Greek phonetic alphabet (Alpha, Bravo, Charlie, etc), which was quite confusing, and then returned to using female names in 1953. Naming storms only after women came to an end in 1978 when men’s and women’s names were included in the Eastern North Pacific storm lists. In 1979, both male and female names were introduced into the lists for the Atlantic and Gulf of Mexico.