Happy #WeatherWednesday everybody. The last write-up was about Hurricane Ike on the 9th year anniversary of landfall in Texas! Today we stay on the category of hurricanes. We call hurricanes by name, a practice popularized in the early 1950s. How are they named and how do hurricane names sometimes get retired?
As most of you know, tropical cyclones with maximum sustained winds of 74 mph or more are called hurricanes in the eastern Pacific and the northern Atlantic Oceans. However, they are recognized and named before they strengthen to this point. NHC (National Hurricane Center) recognizes any areas of organized convection in circular flow as tropical depressions. Once known as a depression, the NHC will update their probability of intensification to a tropical storm several times per day. If the depression reaches tropical storm intensity at 39mph+ sustained winds then it is given a name! This name will be associated with this storm for the rest of its life until it no longer has an organized center of low pressure.
When naming tropical storms in the N. Atlantic, the WMO (World Meteorological Organization) simply has a list of names for each year that are alphabetized and alternate between male and female names. Every odd year begins with a female “A” name, and even years start with a male “A.” There is one name for each letter except for the letters Q, U, Y and Z, which are unused. As there is a list of storm names already set for a year, there are lists of names picked for the following five years. These six lists are rotated so that it doesn’t get too complicated. Unless any name on the list gets retired, the same exact list of names gets used every 6 years. In the event all names on the list are used and we see additional storms (like 2005), the Greek Alphabet is used as names. For the E. Pacific, storms are named in a similar process except with completely different names. There are Y and Z names on the list here, and the odd years start with male names & even years start with female.
Particularly deadly and damaging hurricanes and even possibly tropical storms will see their name retire and have a new name replace their spot in the recyclable list. This policy began in 1955 after 1954 hurricanes Carol, Edna, and Hazel caused nearly a billion dollars of damage and several hundred known deaths combined. An average of one Atlantic name per yearly list is retired and replaced. The Hurricane Committee of WMO decides whether or not a name is retired. The storms whose names are retired are remembered as infamies due to their huge deadly and damaging impacts on life and property.
Most of the retired names are major hurricanes (category 3-5), but a few make the list as cat-1 or 2. Although somewhat controversial, Tropical Storms Allison and Erika even got retired due to deadly flooding or mudslides. On the dishonorable list of retired names you can see names like David, Allen, Mitch, Andrew, Floyd, Charley, Ivan, Katrina, Rita, Wilma, Ike, and Sandy. The 2000s decade was by far the most active for retiring names since the 50s. Although this decade has been slow to retire names, 2017 likely will retire a few names like Harvey, Irma and Maria.