Editing Thunderstorm (section)

===Supercells===
{{Main|Supercell}}
[[File:Thunderhead.anvil.jpg|thumb|The setting sun illuminates the top of a classic anvil-shaped thunderstorm cloud in eastern [[Nebraska]], United States.]]

Supercell storms are large, usually [[severe weather|severe]], quasi-steady-state storms that form in an environment where wind speed or wind direction varies with height ("[[wind shear]]"), and they have separate downdrafts and updrafts (i.e., where its associated precipitation is not falling through the updraft) with a strong, rotating updraft (a "[[mesocyclone]]"). These storms normally have such powerful updrafts that the top of the supercell storm cloud (or anvil) can break through the [[troposphere]] and reach into the lower levels of the [[stratosphere]]. Supercell storms can be {{convert|24|km|mi|0}} wide. Research has shown that at least 90&nbsp;percent of supercells cause [[severe weather]].<ref name="motion">{{cite web|url=http://www.crh.noaa.gov/images/unr/soo/scm/ZB06.pdf|title=Operational Forecasting of Supercell Motion: Review and Case Studies Using Multiple Datasets|author=Jon W. Zeitler|author2=Matthew J. Bunkers|name-list-style=amp|date=March 2005|access-date=30 August 2009|publisher=[[National Weather Service]] Forecast Office, [[Riverton, Wyoming]]}}</ref> These storms can produce destructive [[tornado]]es, extremely large [[hail]]stones ({{convert|10|cm|in|0|disp=or}} diameter), [[straight-line wind]]s in excess of {{convert|130|km/h|mph|abbr=on}}, and [[flash flood]]s. In fact, research has shown that most tornadoes occur from this type of thunderstorm.<ref>{{cite web|date=4 October 1999|url=http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/svr/type/spr/home.rxml |title=Supercell Thunderstorms|work=Weather World 2010 Project|publisher=University of Illinois|access-date=23 August 2006}}</ref> Supercells are generally the strongest type of thunderstorm.<ref name="tsbasics"/>