Parts of a Supercell – Thunderstorm Diagram to Label

All 11 parts on the diagram

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Parts of the cloud 6

Anvil The flat, spreading top of the storm cloud.
Overshooting top A dome above the anvil, pushed up by a very strong updraft.
Wall cloud A local, lasting lowering of cloud from the rain-free base.
Rain-free base The flat cloud base under the updraft, where no rain is seen.
Flanking line Cumulus towers in a stair-step line joined to the main tower.
Mammatus Rounded, smooth pouches hanging from the underside of the anvil.

Moving air and rain 5

Updraft Rising air; in a supercell the updraft is tilted and rotating.
Mesocyclone The rotation of the updraft, what sets a supercell apart.
Precipitation core The area of heaviest rain and hail.
Forward flank downdraft The main downdraft, in the leading part where the heavy rain falls.
Rear flank downdraft Dry air sinking on the back side and wrapping round the rotation.

How this list was compiled: Every name checked on 2026-09-30 in at least two of these. (1) NOAA National Weather Service, Norman, A Comprehensive Glossary of Weather Terms for Storm Spotters, https://www.weather.gov/oun/spotterglossary (anvil, overshooting top, updraft, mesocyclone, wall cloud, rain-free base, forward flank downdraft, rear flank downdraft, flanking line, mammatus, precipitation core). (2) NOAA National Severe Storms Laboratory, Thunderstorm Types, https://www.nssl.noaa.gov/education/svrwx101/thunderstorms/types/ (a supercell’s tilted, rotating updraft; mesocyclone). (3) NOAA National Weather Service, Amarillo, Supercell thunderstorms, https://www.weather.gov/ama/supercell (anvil, mesocyclone, wall cloud, rain free base, rear flank downdraft). (4) Wikipedia, Supercell, https://en.wikipedia.org/wiki/Supercell (overshooting top, anvil, precipitation-free base, wall cloud, mammatus, forward and rear flank downdrafts, flanking line, precipitation core). (5) NOAA JetStream, Types of Thunderstorms, https://www.noaa.gov/jetstream/tstrmtypes (wall cloud, rain-free base, the supercell’s updraft). Licence: own work

The drawing: Drawn for this site on 2026-09-30 from plain geometry. Own original drawing; nothing is traced or copied. Licence: own work

How it works

The parts of a supercell are drawn here from the side, with the storm moving to the right: the cloud from anvil to wall cloud, and the air that rises, turns and sinks inside it.

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One rotating updraft

A supercell feeds on a single updraft that is tilted and rotating. That rotation is the mesocyclone, and it is what sets a supercell apart from other thunderstorms. Where the rising air is strongest it punches a dome, the overshooting top, above the anvil.

Two downdrafts

The forward flank downdraft is the main one, in the leading part where the heavy rain and hail fall. The rear flank downdraft is dry air sinking on the back side and wrapping round the rotation. Under the updraft the base is flat and rain-free, and a wall cloud may hang from it.

Questions and answers

What are the parts of a supercell?

A main updraft tower that rotates (the mesocyclone), an anvil with an overshooting top, a flanking line of smaller towers, a rain-free base with a wall cloud, a precipitation core, and two downdrafts, forward flank and rear flank.

What makes a supercell different from other thunderstorms?

Its updraft rotates. The National Weather Service describes a deep, persistent rotating updraft called a mesocyclone, and says the tilt of the storm keeps the updraft and the downdraft apart, which lets a supercell last for hours.

What is a wall cloud?

A local, lasting lowering of cloud that hangs from the rain-free base, under the main updraft. Wall clouds are not found only on supercells.

What is the overshooting top?

A dome that rises above the anvil over the strongest part of the updraft. It shows that the updraft is strong enough to push past the level where the anvil spreads out.