Storm clouds

From Wikipedia's list of cloud types here

Accessory cloud – cloud that is attached to and
develops on body of main cloud

Anvil – the top flatter part of a cumulonimbus (Cb)
cloud

Anvil dome – the overshooting top on a Cb that is
often present on a supercell

Anvil rollover – (slang) circular protrusion attached
to underside of anvil

Arcus cloud – arch or a bow shape, attached to
cumulus, thick with ragged edges

Backsheared anvil – (slang) anvil that spreads upwind,
indicative of extreme weather

Clear slot (or dry slot) - an evaporation of clouds as
a rear flank downdraft descends and dries out cloud
and occludes around a mesocyclone

Cloud tags – ragged detached portions of cloud

Collar cloud – rare ring shape surrounding upper part
of wall cloud

Condensation funnel - the cloud of a funnel cloud
aloft or a tornado

Cumulus – heaped clouds

Cumulus congestus – moderate development and heaped
into cauliflower shapes

Cumulus fractus – ragged detached portions of cumulus
cloud

Cumulus humilis - small, low, flattened cumulus, early
development

Cumulus mediocris - medium-sized cumulus with small
bulges at the top

Cumulus pannus - shredded sections attached to main
cumulus cloud

Cumulus pileus - capped – hood shaped cumulus cloud

Cumulus praecipitatio - cumulus whose precipitation
reaches the
ground

Cumulus radiatus – cumulus arranged in parallel lines

Cumulus tuba - column hanging from the bottom of
cumulus

Cumulus velum - cumulus displaying an undulating
pattern

Cumulonimbus – heaped towering rain-bearing clouds
that stretch to
the upper levels

Cumulonimbus calvus – cumulonimbus whose upper parts
have lost their shape

Cumulonimbus capillatus - Cb whose upper parts have
taken on a cirrus-like form

Cumulonimbus incus – Cb with anvil aloft

Cumulonimbus mammutus - pouch-like protrusions that
hang from under an anvil

Cumulonimbus pannus - shredded sections attached to
main Cb cloud

Cumulonimbus pileus - capped – hood shaped
cumulonimbus cloud

Cumulonimbus praecipitatio - Cb whose precipitation
reaches the ground

Cumulonimbus spissatus - cumulonimbus with a thick
grey appearance

Cumulonimbus tuba - column hanging from the bottom of
cumulonimbus

Cumulonimbus velum - cumulonimbus displaying an
undulating pattern

Debris cloud – rotating ‘cloud’ of debris found at
base of tornado

Hail fog - a shallow surface layer of fog that
sometimes forms in vicinity of deep hail accumulation,
can be very dense

Inflow band - a laminar band marking inflow to a Cb,
can occur at lower or mid levels of tower

Inverted cumulus - cumulus which has transferred
momentum from an exceptionally intense Cb tower and is
convectively growing on the underside of an anvil

Fractonimbus - dark ragged clouds under base of
precipitation cloud.

Funnel cloud – rotating funnel of cloud hanging from
under Cb, not making contact with ground

Knuckles – lumpy protrusion that hangs from edge or
underside of anvil

Roll cloud – elongated, low-level, tube shaped,
horizontal cloud

Rope cloud – (slang) narrow, sometimes twisted funnel
type cloud seen after tornado dissipates

Scud cloud – ragged detached portions of cloud

Shelf cloud – wedge shaped cloud often attached to the
underside of Cb

Stratus fractus – ragged detached portions of stratus
cloud

Striations - a groove or band of clouds encircling an
updraft tower, indicative of rotation

Tail cloud - an area of condensation consisting of
laminar band and cloud tags extending from a wall
cloud towards a precipitation core

Towering cumulus (TCu) - a large cumulus cloud with
great vertical development, usually with a
cauliflower-like appearance, but lacking the
characteristic anvil of a Cb

Wall cloud – distinctive fairly large lowering of the
rain free base of a Cb, often rotating