Editing Cyclone (section)

====Subtropical====
[[File:Alex 2016-01-13 1530Z.jpg|thumb|right|[[Hurricane Alex (2016)|Subtropical Storm Alex]] in the north Atlantic Ocean in January [[2016 Atlantic hurricane season|2016]]]]

{{main|Subtropical cyclone}}
A '''subtropical cyclone''' is a weather system that has some characteristics of a [[tropical cyclone]] and some characteristics of an [[extratropical cyclone]]. They can form between the equator and the 50th parallel.<ref name = "A6"/> As early as the 1950s, meteorologists were unclear whether they should be characterized as tropical cyclones or extratropical cyclones, and used terms such as quasi-tropical and semi-tropical to describe the cyclone hybrids.<ref>{{cite journal |doi=10.1175/1520-0493(1973)101<0380:R>2.3.CO;2 |title=Reply |date=1973 |last1=Spiegler |first1=David B. |journal=Monthly Weather Review |volume=101 |issue=4 |page=380 |bibcode=1973MWRv..101..380S |doi-access=free }}</ref> By 1972, the [[National Hurricane Center]] officially recognized this cyclone category.<ref>{{cite journal |doi=10.1175/1520-0493(1973)101<0323:AHSO>2.3.CO;2 |title=Atlantic Hurricane Season of 1972 |date=1973 |last1=Simpson |first1=R. H. |last2=Hebert |first2=Paul J. |journal=Monthly Weather Review |volume=101 |issue=4 |pages=323–333 |bibcode=1973MWRv..101..323S |doi-access=free }}</ref> Subtropical cyclones began to receive names off the [[Tropical cyclone naming|official tropical cyclone list]] in the Atlantic Basin in 2002.<ref name = "A6"/> They have broad wind patterns with maximum sustained winds located farther from the center than typical tropical cyclones, and exist in areas of weak to moderate temperature gradient.<ref name="A6">{{cite web|author=Chris Landsea|url=http://www.aoml.noaa.gov/hrd/tcfaq/A6.html|title=Subject: A6) What is a sub-tropical cyclone?|access-date=2009-12-27|date=2009-02-06|publisher=[[Atlantic Oceanographic and Meteorological Laboratory]]|author-link=Chris Landsea|archive-date=2011-10-11|archive-url=https://web.archive.org/web/20111011042947/http://www.aoml.noaa.gov/hrd/tcfaq/A6.html|url-status=live}}</ref>

Since they form from extratropical cyclones, which have colder temperatures aloft than normally found in the tropics, the sea surface temperatures required is around 23&nbsp;degrees Celsius (73&nbsp;°F) for their formation, which is  three degrees Celsius (5&nbsp;°F) lower than for tropical cyclones.<ref name="HistSubTropCyclones">{{cite web
 |title = A Fifty year History of Subtropical Cyclones
 |author = David Mark Roth
 |publisher = Hydrometeorological Prediction Center
 |date = 2002-02-15
 |url = http://www.wpc.ncep.noaa.gov/research/roth/Subpreprint.pdf
 |access-date = 2006-10-04
 |archive-date = 2021-04-17
 |archive-url = https://web.archive.org/web/20210417020816/https://www.wpc.ncep.noaa.gov/research/roth/Subpreprint.pdf
 |url-status = live
 }}</ref> This means that subtropical cyclones are more likely to form outside the traditional bounds of the hurricane season. Although subtropical storms rarely have hurricane-force winds, they may become tropical in nature as their cores warm.<ref name = "AOML FAQ A6">{{cite web|author = Chris Landsea|publisher = [[NOAA]]|title = Frequently Asked Questions: What is a sub-tropical cyclone?|access-date = 2009-12-27|date = 2009-02-06|url = http://www.aoml.noaa.gov/hrd/tcfaq/A6.html|author-link = Chris Landsea|archive-date = 2011-10-11|archive-url = https://web.archive.org/web/20111011042947/http://www.aoml.noaa.gov/hrd/tcfaq/A6.html|url-status = live}}</ref>