Editing Supercell (section)

===Structure===
[[File:Supercell.svg|thumb|upright=1.5|Structure of a supercell. Northwestward view in the [[Northern Hemisphere]]]]

====Overshooting top====
{{main|Overshooting top}}
This "dome" feature appears above the strongest updraft location on the anvil of the storm. It is a result of an updraft powerful  enough to break through the upper levels of the troposphere into the lower [[stratosphere]].<ref>{{cite journal|last1= Shenk|first1= W. E.|date= 1974|title= Cloud top height variability of strong convective cells|journal= [[Journal of Applied Meteorology]]|volume = 13|issue= 8|pages= 918{{ndash}}922| doi=10.1175/1520-0450(1974)013<0917:cthvos>2.0.co;2 |bibcode = 1974JApMe..13..917S |doi-access= free}}</ref><ref name="Overshooting Tops">{{cite web|url=https://www.eumetsat.int/website/home/Data/Training/TrainingLibrary/DAT_2042700.html|title=Overshooting Tops – Satellite-Based Detection Methods|publisher=[[EUMETSAT]]|date=9 June 2011|access-date=10 May 2019|archive-date=10 May 2019|archive-url=https://web.archive.org/web/20190510090501/https://www.eumetsat.int/website/home/Data/Training/TrainingLibrary/DAT_2042700.html|url-status=dead}}</ref> An observer at ground level and close to the storm may be unable to see the overshooting top because the anvil blocks the sight of this feature. The overshooting is visible from satellite images as a "bubbling" amidst the otherwise smooth upper surface of the anvil cloud.

====Anvil====
An anvil forms when the storm's updraft collides with the upper levels of the lowest layer of the atmosphere, or the tropopause, and has nowhere else to go due to the laws of fluid dynamics- specifically pressure, humidity, and density, in simple terms, the packet of air has lost its buoyancy and cannot rise higher. The anvil is very cold (-30°C) and virtually precipitation-free even though [[virga]] can be seen falling from the forward sheared anvil. Since there is so little moisture in the anvil, winds can move freely. The clouds take on their anvil shape when the rising air reaches {{convert|50000|-|70000|ft|m|sigfig=3|order=flip}} or more. The anvil's distinguishing feature is that it juts out in front of the storm like a shelf. In some cases, it can even shear backwards, called a backsheared anvil, another sign of a very strong updraft.

==== Precipitation-free base ====
This area, typically on the southern side of the storm in North America, is relatively precipitation-free. This is located beneath the main updraft, and is the main area of inflow. While no precipitation may be visible to an observer, large hail may be falling from this area. A region of this area is called the Vault. It is more accurately called the main updraft area.

==== Wall cloud ====
The [[wall cloud]] forms near the downdraft/updraft interface. This "interface" is the area between the ''precipitation area'' and the ''precipitation-free base.'' Wall clouds form when rain-cooled air from the downdraft is pulled into the updraft. This wet, cold air quickly saturates as it is lifted by the updraft, forming a cloud that seems to "descend" from the precipitation-free base. Wall clouds are common and are not exclusive to supercells; only a small percentage actually produce a tornado, but if a storm does produce a tornado, it usually exhibits wall clouds that persist for more than ten minutes. Wall clouds that seem to move violently up or down, and violent movements of cloud fragments (scud or fractus) near the wall cloud, are indications that a tornado could form.

==== Mammatus clouds ====
[[Mammatus cloud|Mammatus]] (Mamma, Mammatocumulus) are bulbous or pillow-like cloud formations extending from beneath the anvil of a thunderstorm. These clouds form as cold air in the anvil region of a storm sinks into warmer air beneath it. Mammatus are most apparent when they are lit from one side or below and are therefore at their most impressive near sunset or shortly after sunrise when the sun is low in the sky. Mammatus are not exclusive to supercells and can be associated with developed thunderstorms and cumulonimbus.

==== Forward flank downdraft (FFD) ====
[[File:Supercell-above.svg|thumb|Diagram of supercell from above. RFD: ''rear flank downdraft'', FFD: ''front flank downdraft'', V: ''V-notch'', U: ''Main Updraft'', I: ''Updraft/Downdraft Interface'', H: ''hook echo'']]

This is generally the area of heaviest and most widespread precipitation. For most supercells, the precipitation core is bounded on its leading edge by a [[shelf cloud]] that results from rain-cooled air within the precipitation core spreading outward and interacting with warmer, moist air from outside of the cell. Between the precipitation-free base and the FFD, a "vaulted" or "cathedral" feature can be observed. In ''high precipitation supercells'' an area of heavy precipitation may occur beneath the main updraft area where the vault would alternately be observed with classic supercells.

==== Rear flank downdraft (RFD) ====
{{Main|Rear flank downdraft}}

The rear flank downdraft of a supercell is a very complex and not yet fully understood feature. RFDs mainly occur within classic and HP supercells although RFDs have been observed within LP supercells. The RFD of a supercell is believed to play a large part in tornadogenesis by tightening existing rotation within the surface mesocyclone. RFDs are caused by mid-level steering winds of a supercell colliding with the updraft tower and moving around it in all directions; specifically, the flow that is redirected downward is referred to as the RFD. This downward surge of relatively cool mid-level air, due to interactions between dew points, humidity, and condensation of the converging of air masses, can reach very high speeds and is known to cause widespread wind damage. The radar signature of an RFD is a hook-like structure where sinking air has brought with it precipitation.

==== Flanking line ====
{{Main|flanking line (meteorology)}}
A flanking line is a line of smaller [[Cumulonimbus cloud|cumulonimbi]] or cumulus that form in the warm rising air pulled in by the main updraft. Due to convergence and lifting along this line, [[landspouts]] sometimes occur on the outflow boundary of this region.