1. Stratus Nebulosus

Low-lying clouds which are flat, hazy, and formless. They may produce light drizzle or snow.

Basically fog which is above ground level.

The cumulus is the archetypal cloud: fluffy and white with a clearly defined shape.

Cumulus means "heap" in Latin, referring to their distinctive appearance.

But the cumulus has a few different stages of evolution...

2. Cumulus Fractus

The first stage of cumulus clouds. These are quite "ragged" in appearance, and lack the definitive shape of a typical cumulus cloud.

3. Cumulus Humilis

The next stage. Their appearance is fairly flat and shallow, but they are more clearly defined.

Hence the name humilis, meaning humble.

4. Cumulus Mediocris

The next stage of the cumulus. These have greater vertical depth than the humilis; the typical cartoon cloud.

5. Cumulus Congestus

An even more advanced stage of the cumulus. These are very large clouds which can tower into the atmosphere.

6. Altocumulus Stratiformis

Altocumulus clouds are formed of small, shallow, bunched-up masses.

In the altocumulus stratiformis these bunches form very close together in wide, partially transparent layers.

Often followed by rainfall.

7. Stratocumulus Undulatus

The stratocumulus is a cloud formation of big, rounded masses, which are lower and much larger than the altocumulus.

The undulatus stratocumulus appears as parallel lines of these formations.

8. Cirrostratus

Very high-level, thin, and transparent clouds which cover large areas of the sky.

Cirrus are another form of high-level clouds which appear in wispy or hair-like formations.

9. Such as the cirrus fibratus, so called because of its fibrous appearance.

10. Or the cirrus uncinus, which appears like the tail of a horse.

The cumulonimbus is an evolution of the previously mentioned cumulus congestus.

They are huge, with bases many kilometres wide, and have several subvariants.

11. Cumulonimbus Calvus

Not huge by cumulonimbus standards but still an extremely large cloud, the calvus is distinguished by its clearly defined edges and dome-shaped top.

Usually brings rain, snow, or hail, and they can also produce lightning.

12. Cumulonimbus Incus

The famous anvil cloud - so called because of its shape - and the next stage of the cumulonimbus.

They soar tens of thousands of feet into the atmosphere and can produce very dangerous weather conditions - a powerful stormcloud.

13. Mammatus

A distinctive pattern which is found on other cloud formations, rather than being a formation of its own.

For example, on the bottom of a cumulonimbus.

Distinguished by the "pouches" of cloud which look like they're hanging down.

14. Arcus

Not common but they look incredible. These are low-lying, long, and thin clouds which precede powerful thunderstorms.