Editing Wall cloud (section)

=== Wall cloud vs. shelf cloud ===
[[File:Rolling-thunder-cloud.jpg|thumb|left|A shelf cloud over [[Enschede]], [[Netherlands]]]]
Many storms contain [[shelf cloud]]s, which are often mistaken for wall clouds since an approaching shelf cloud appears to form a wall made of clouds and may contain turbulent motions.<ref name="Training"/> Wall clouds are inflow clouds and tend to slope inward, or toward the precipitation area of a storm. Shelf clouds, on the other hand, are [[outflow (meteorology)|outflow]] clouds that jut outward from the storm, often as [[gust front]]s. Also, shelf clouds tend to move outward away from the precipitation area of a storm.

Shelf clouds most often appear on the leading edge of a thunderstorm as they are formed by condensation from the cool outflow of the storm that lifts warmer air in the ambient environment (at the [[outflow boundary]]). When present in a supercell thunderstorm these shelf clouds on the leading edge of a storm are associated with the [[forward flank downdraft]] (FFD). Shelf clouds in supercells also form with the [[rear flank downdraft]] (RFD), although these tend to be more transitory and smaller than shelf clouds on the forward side of a storm.<ref>{{cite web |last = Drummond |first = David |title = Advanced Module |work = Skywarn Storm Spotter Guides |url = http://spotterguides.us/advanced/advanced06.htm |access-date = 2014-06-01 |archive-url =https://web.archive.org/web/20040111050931/http://spotterguides.us/advanced/advanced06.htm|url-status = dead |archive-date =2004-01-11}}</ref><ref>{{cite web |title = The Tornado |work = Thunderstorms and Severe Weather |publisher = the University of Texas |date = 29 Jun 1998 |url = http://www.tsgc.utexas.edu/stars/tornado.html |access-date = 2014-06-01 }}</ref> A wall cloud will usually be at the rear of the storm, though small, rotating wall clouds (a feature of a [[mesovortices|mesovortex]]) can occur within the leading edge (typically of a quasi-linear convective system (QLCS) or [[squall line]]) on rare occasion.<ref name="Training">Chance Hayes, National Weather Service Wichita, Kansas. "Storm Fury on the Plains." Storm Spotter Training. 4H Building, Salina, Kansas. 22 Feb. 2010. Lecture.</ref> 
{{clr}}