Editing Subtropical cyclone (section)

===Transition from extratropical===
By gaining tropical characteristics, an extratropical low may transit into a subtropical depression or storm. A subtropical depression/storm may further gain tropical characteristics to become a pure tropical depression or storm, which may eventually develop into a hurricane, and there are at least ten cases of tropical cyclones transforming into a subtropical cyclone ([[Tropical Storm Gilda (1973)|Tropical Storm Gilda]] in 1973, [[Subtropical Storm Four (1974)|Subtropical Storm Four]] in 1974, [[1981 Atlantic hurricane season#Tropical Storm Jose|Tropical Storm Jose]] in 1981, [[Hurricane Klaus (1984)|Hurricane Klaus]] in 1984, [[Tropical Storm Allison]] in 2001, [[Tropical Storm Lee (2011)|Tropical Storm Lee]] in 2011, [[2013 Atlantic hurricane season#Hurricane Humberto|Hurricane Humberto]] in 2013, [[2016 Atlantic hurricane season#Tropical Storm Ian|Tropical Storm Ian]] in 2016, [[Typhoon Jelawat (2018)|Typhoon Jelawat]] in 2018, and [[Typhoon Surigae]] in 2021). There have also been three recorded cases of a storm transitioning from tropical to extratropical back to a subtropical cyclone; as seen with the [[1970 Caribbean–Azores hurricane|Caribbean–Azores hurricane]] in 1970, [[1980 Atlantic hurricane season#Hurricane Georges|Hurricane Georges]] in 1980, and [[Hurricane Beryl (2018)|Hurricane Beryl]] in 2018. Generally, a tropical storm or tropical depression is not called subtropical while it is becoming extratropical and vice versa, after hitting either land or colder waters. This transition normally requires significant instability through the atmosphere, with temperature differences between the underlying ocean and the mid-levels of the [[troposphere]] requiring over 38&nbsp;°C, or 68&nbsp;°F, of contrast in this roughly {{convert|5900|m|ft|sp=us}} layer of the lower atmosphere. The [[mode (statistics)|mode]] of the sea surface temperatures that subtropical cyclones form over is {{convert|23|C|F}}.<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> Transition from subtropical cyclones into fully tropical cyclones occurs only in very rare cases over the south Atlantic Ocean, such as [[Hurricane Catarina]] in 2004.<ref name="SAtlSTs"/>