There’s just something about their majestic yet often foreboding appearance that captivates people around the world.
Yet despite clouds appearing in our skies daily
there are some incredible cloud formations that only a select few of us will ever be lucky enough to see
– cloud formations which are so rare science has yet to fully understand them.
If you’ve seen any of them then you ought to consider yourself incredibly lucky for most of us are still waiting…
1. Nacreous Clouds
Often known as Mother of Pearl clouds, nacreous clouds are an extremely rare sight. They form between nine and sixteen miles high in the atmosphere and give off a breathtaking iridescent glow. While they form mostly in the polar regions, they have been known to form across the globe during winter and at high altitudes. These beautiful clouds tend to shine brightly just before dawn or in the two hours just after sunset, making for an unforgettable sight.
2. Mammatus Clouds
Mammatus clouds can be incredibly ominous in appearance however prior to popular belief they do not signal the start of a tornado, though they do occur most frequently before or after thunderstorms. They’re distinguishable by their pouch-like appearance which is caused by air sinking and the formation can stretch for hundreds of miles in any direction, often blotting out light with their opacity. Most frequently, mammatus clouds are made up primarily of ice but in some cases they’ve been known to be a mixture of ice and liquid.
3. Noctilucent Clouds
Noctilucent clouds, also known as polar mesopheric clouds, are one of the rarest cloud formations there is. Their name noctilucent roughly means night shining in Latin. Noctilucent clouds form primarily in polar regions and are only visible after sunset when the suns rays reflect off of them, illuminating the night sky and giving them their name. These magnificent clouds form just on the very edge of space, about 47-53 miles high, and are most commonly observed in the summer months.
4. Cirrus Kelvin-Helmholtz Wave Clouds
Kelvin-Helmholtz occur only on the rarest of occasions and as a result they have yet to be widely photographed. They’re caused by shearing winds up at cloud level which move at varying speeds. When higher winds howl faster than the lower winds this causes the trough of the clouds to bend, pushing them over into a distance wave-like formations. These distinctive clouds can form anywhere in the world however when they do they only stick around for a few short minutes before vanishing.
5. Lenticular Clouds
Lenticular clouds are stationary, lens-shaped clouds which form high in the atmosphere. They usually form when moist air passes over a mountain range and is heated adiabatically (meaning without any transference of heat energy) as it descends. Due to their strange appearance, lenticular clouds are thought to be the explanation for many UFO sightings, making them a popular sight with many UFO believers.
6. Roll Clouds
Associated with a thunderstorm gust front or often a cold front, roll clouds are a low, horizontal, tube-shaped cloud which seemingly roll across the sky. They form when cool air sinks from a storm cloud’s downdraft and spreads out with the leading edge being called the gust front. This cool air then undercuts warm air, causing it to condense and form a cloud which then seems to roll in a tubular shape, making for a memorable and often frightening sight.
7. Undulatus Asperatus Clouds
Proposed in 2009, undulatus aspueratus clouds are likely to be the newest classification of cloud and will be the newest recognised cloud formation since 1951. Their name roughly translates to ‘roughened or agitated waves’ and comes from their wave-like appearance. The dark, ominous-looking clouds appear storm-like however they tend to pass without a storm occurring and simply dissipate. For the most part, these clouds are not seen outside of the US.
Question of the Day:
Have you ever seen strange clouds?
Let us know in the comments below!