Editing Cirrus cloud (section)

=== Thunderstorms ===
[[File:Cirren von Cumulonimbus-Amboss und Cu&Sc.JPG|thumb|alt=A picture showing the cirrus clouds lancing out from the anvil of the thunderstorm, taken just before the lower mass of the cumulonimbus cloud went over the photographer|White cirrus in an anvil cloud]]
[[Thunderstorm]]s can form dense cirrus at their tops. As the cumulonimbus cloud in a thunderstorm grows vertically, the liquid water droplets freeze when the air temperature reaches the [[freezing point]].<ref name="lydolph-122">{{harvnb|Lydolph|1985|p=122}}</ref> The [[anvil cloud]] takes its shape because the [[temperature inversion]] at the tropopause prevents the warm, moist air forming the thunderstorm from rising any higher, thus creating the flat top.<ref name="G&N-212">{{harvnb|Grenci|Nese|2001|p=212}}</ref> In the tropics, these thunderstorms occasionally produce copious amounts of cirrus from their anvils.<ref>{{cite web|title=Computer-simulated Thunderstorms with Ice Clouds Reveal Insights for Next-generation Computer Models |url=http://www.pnl.gov/science/highlights/highlight.asp?id=709 |work=Atmospheric Sciences & Global Change Division Research Highlights |publisher=Pacific Northwest National Laboratory |access-date=30 January 2011 |page=42 |date=December 2009 |archive-url=https://web.archive.org/web/20110514115603/http://www.pnl.gov/science/highlights/highlight.asp?id=709 |archive-date=14 May 2011 }}</ref> High-altitude winds commonly push this dense mat out into an anvil shape that stretches [[downwind]] as much as several kilometers.<ref name="G&N-212"/>

Individual cirrus cloud formations can be the remnants of anvil clouds formed by thunderstorms. In the dissipating stage of a cumulonimbus cloud, when the normal column rising up to the anvil has evaporated or dissipated, the mat of cirrus in the anvil is all that is left.<ref name="G&N-213">{{harvnb|Grenci|Nese|2001|p=213}}</ref>