10 Very Rare Cloud Formations
1. Nacreous Clouds
2. Mammatus Clouds
3. Altocumulus Castelanus
4. Noctilucent Clouds
5. Mushroom Clouds
6. Cirrus Kelvin-Helmholtz
7. Lenticular Clouds
8. Roll Clouds
9. Shelf Clouds
10. Stratocumulus Clouds
Hmm, I should keep my eye out for these from now on, they look interesting.
(Source: collthings.co.uk, via dottily)
