The terms
hurricane and
typhoon are regionally specific names for a strong "tropical cyclone". A tropical cyclone is the generic term for a non-frontal synoptic scale low-pressure system over tropical or sub-tropical waters with organized convection (i.e. thunderstorm activity) and definite cyclonic surface wind circulation
Naming conventions are
:
- hurricane (the North Atlantic Ocean, the Northeast Pacific Ocean east of the dateline, or the South Pacific Ocean east of 160E)
- typhoon (the Northwest Pacific Ocean west of the dateline)
- severe tropical cyclone (the Southwest Pacific Ocean west of 160E or Southeast Indian Ocean east of 90E)
- severe cyclonic storm (the North Indian Ocean)
- tropical cyclone (the Southwest Indian Ocean)
A typhoon or tropical storm is a
tropical cyclone that forms in the northwestern
Pacific Ocean. The basin is demarcated within the Pacific Ocean from Asia, north of the equator, and west of the
International Date Line.
Storms from the Eastern and Central Pacific crossing the date line are re-designated as typhoons; prior to entering the basin they are respectively called "hurricanes" and "severe tropical cyclones."
This basin features the
strongest cyclones on record.
Typhoon seasons include the entirety of the calendar year. Most storms tend to form between May and November, although they can occur at other times of the year as well.
Etymology
The word "
typhoon" may come from the
Hakka dialect phrase "tai foong", or the
Cantonese phrase "dai fung", or the
Mandarin "taí fēng," all with the meaning "Big Wind" ().
Other possible origins of the word include the Greek
Typhon, the god of the winds, who personifies storm thunder winds. The Arabic, Persian, and Hindi terms
tufan may have been borrowed from the Greek. In
old Turkic script the word Tufan is also recorded.
In current Mandarin Chinese, typhoon is táifēng (; Cantonese
Jyutping: toi
4fung
1), and in Japanese it is .
Climatology
Nearly one-third of the world's tropical cyclones form within the Western Pacific.
This makes this basin the most active.
Pacific typhoons have formed year round, with peak months from August to October. The peak months correspond to that of the
Atlantic hurricane seasons. Along with a high storm frequency, this basin also features the most globally
intense storms on record. One of the most recent extraordinary years was
1962.
Paths
Typhoon paths follow three general directions.
- Straight. A general westward path affects the Philippines, southern China, Taiwan, and Vietnam.
- Recurving. Storms recurving affect eastern China, Taiwan, Korea, and Japan.
- Northward. From point of origin, the storm follows a northerly direction, only affecting small islands.
Basin monitoring
The following agencies monitor typhoons:
Name sources
The list of names consists of entries from 17 East Asian nations and the United States who have territories directly affected by typhoons. The submitted names are arranged into five lists; and each list is cycled with each year. Unlike
hurricanes, typhoons are not named after people. Instead, they generally refer to animals, flowers, astrological signs, and a few personal names. However, PAGASA retains its own naming list, which does consist of human names.
Therefore, a typhoon can possibly have two names. Storms that cross the date line from the Central Pacific retain their original name, but the designation of hurricane becomes typhoon. In Japan and Vietnam, typhoons are simply numbered according to the sequence of their occurrence in the calendar year. Hence the third typhoon in a given year is simply "Typhoon No. 3".
See also
