1. Nacreous Clouds
These rare clouds, sometimes called mother-of-pearl clouds, are 15 – 25km (9 -16 miles) high in the stratosphere and well above tropospheric clouds.
2. Mammatus Clouds
Mammatus are pouch-like cloud structures and a rare example of clouds in sinking air. Sometimes very ominous in appearance, mammatus clouds are harmless and do not mean that a tornado is about to form – a commonly held misconception.
3. Altocumulus Castelanus
Also known as jellyfish clouds due to their jellyfish-like appearance. These formed around 17,000 ft due to when the rush of moist air comes from the Gulf Stream and gets trapped between layers of dry air.
4. Noctilucent Clouds
Noctilucent Clouds or Polar Mesopheric Clouds: This is an extroadinarily rare cloud formation that occurs out on the verge of space between 82km to 102 km from the earth’s surface.
5. Mushroom Clouds
A mushroom cloud is a distinctive mushroom-shaped cloud of smoke, condensed water vapor, or debris resulting from a very large explosion.
6. Cirrus Kelvin-Helmholtz
Appearing as a slender, horizontal spiral of cloud, cirrus Kelvin-Helmholtz is one of the most distinctive cloud formations..Average height is around 16,500 ft.
7. Lenticular Clouds
Lenticular clouds, technically known as altocumulus standing lenticularis, are stationary lens-shaped clouds that form at high altitudes.
8. Roll Clouds
A roll cloud is a low, horizontal tube-shaped arcus cloud associated with a thunderstorm gust front, or sometimes a cold front.
9. Shelf Clouds
A shelf cloud is a low, horizontal wedge-shaped arcus cloud.
10. Stratocumulus Clouds
According to the Sapporo Meteorological Observatory, these low-altitude stratocumulus clouds were rolled into long, distinctive ribbons after becoming trapped in air currents.