Editing Cyclone (section)

====Extratropical cyclone====
{{main|Extratropical cyclone}}

An '''extratropical cyclone''' is a [[synoptic scale]] [[Low-pressure area|low-pressure]] weather system that does not have [[tropical cyclone|tropical]] characteristics,<ref>{{cite book |doi=10.1016/B978-0-444-53199-5.00027-0 |chapter=Precipitation |title=Treatise on Water Science |date=2011 |last1=Koutsoyiannis |first1=D. |last2=Langousis |first2=A. |pages=27–77 |isbn=978-0-444-53199-5 }}</ref> as it is connected with [[Surface weather analysis|fronts]] and horizontal [[gradients]] (rather than vertical) in [[temperature]] and [[dew point]] otherwise known as "baroclinic zones".<ref name="ExtraLessonMillUni">{{cite web
 |title = ESCI 241 – Meteorology; Lesson 16&nbsp;– Extratropical Cyclones
 |author =  DeCaria
 |publisher = Department of Earth Sciences, Millersville University, Millersville, Pennsylvania
 |date = 2005-12-07
 |url = http://www.atmos.millersville.edu/~adecaria/ESCI241/esci241_lesson16_cyclones.html
 |access-date = 2006-10-21 |archive-url = https://web.archive.org/web/20060903093420/http://www.atmos.millersville.edu/~adecaria/ESCI241/esci241_lesson16_cyclones.html |archive-date = September 3, 2006}}</ref>

"[[Extratropical]]" is applied to cyclones outside the tropics, in the middle latitudes. These systems may also be described as "mid-latitude cyclones" due to their area of formation, or "post-tropical cyclones" when a tropical cyclone has moved ([[extratropical transition]]) beyond the tropics.<ref name="ExtraLessonMillUni"/><ref name="ExtratropicalPhases">{{cite web
 |title = Synoptic Composites of the Extratropical Transition Lifecycle of North Atlantic TCs as Defined Within Cyclone Phase Space
 |author1 = Robert Hart
 |author2 = Jenni Evans
 |publisher = American Meteorological Society
 |year = 2003
 |url = http://ams.confex.com/ams/pdfpapers/70524.pdf
 |access-date = 2006-10-03
 |archive-date = 2011-06-09
 |archive-url = https://web.archive.org/web/20110609164448/http://ams.confex.com/ams/pdfpapers/70524.pdf
 |url-status = live
 }}</ref> They are often described as "depressions" or "lows" by weather forecasters and the general public. These are the everyday phenomena that, along with [[anticyclone]]s, drive weather over much of the Earth.

Although extratropical cyclones are almost always classified as [[baroclinic]] since they form along zones of temperature and dewpoint gradient within the [[westerlies]], they can sometimes become [[barotropic]] late in their life cycle when the temperature distribution around the cyclone becomes fairly uniform with radius.<ref>{{cite web|author=Ryan N. Maue|year=2008|url=http://www.coaps.fsu.edu/~maue/cyclone_ch3.html|title=Chapter 3: Cyclone Paradigms and Extratropical Transition Conceptualizations|access-date=2008-06-15|publisher=[[Florida State University]]|archive-url=https://web.archive.org/web/20080510210146/http://www.coaps.fsu.edu/~maue/cyclone_ch3.html |archive-date=2008-05-10}}</ref> An extratropical cyclone can transform into a subtropical storm, and from there into a tropical cyclone, if it dwells over warm waters sufficient to warm its core, and as a result develops central convection.<ref name = "AOML FAQ A7-2">{{cite web|author = [[Atlantic Oceanographic and Meteorological Laboratory]], Hurricane Research Division|title = Frequently Asked Questions: What is an extra-tropical cyclone?|publisher = [[NOAA]]|access-date = 2006-07-25|url = http://www.aoml.noaa.gov/hrd/tcfaq/A7.html|archive-date = 2007-02-09|archive-url = https://web.archive.org/web/20070209121005/http://www.aoml.noaa.gov/hrd/tcfaq/A7.html|url-status = live}}</ref> A particularly intense type of extratropical cyclone that strikes during winter is known colloquially as a ''[[nor'easter]]''.