1. Lenticular clouds (Altocumulus lenticularis)
stationary lens-shaped clouds that form in the troposphere, normally in perpendicular alignment to the wind direction. sometimes people refers it as UFO cloud because of the saucer shape of the cloud.
2. Roll Cloud
A roll cloud is a low, horizontal, tube-shaped, and relatively rare type of arcus cloud. Roll clouds usually appear to be “rolling” about a horizontal axis. One of the most famous frequent occurrences is the Morning Glory cloud in Queensland, Australia, which can occur up to four out of ten days in October, Coastal roll clouds have been seen in many places, including California, the English Channel, Shetland Islands, the North Sea coast, and coastal regions of Australia.
3. Shelf Cloud
A shelf cloud is a low, horizontal, wedge-shaped arcus cloud. A shelf cloud is attached to the base of the parent cloud, which is usually a thunderstorm, A shelf cloud usually appears on the leading edge of a storm, and a wall cloud will usually be at the rear of the storm.
4. Mammatus Cloud
mammatocumulus (meaning “mammary cloud” or “breast cloud”), is a meteorological term applied to a cellular pattern of pouches hanging underneath the base of a cloud. The name mammatus is derived from the Latin mamma (meaning “udder” or “breast”)
5. Noctilucent Clouds
Night clouds or noctilucent clouds are tenuous cloud-like phenomena that are the “ragged edge” of a much brighter and pervasive polar cloud layer called polar mesospheric clouds in the upper atmosphere, visible in a deep twilight. They are made of crystals of water ice. Noctilucent roughly means night shining in Latin. They are most commonly observed in the summer months at latitudes between 50° and 70° north and south of the equator. They can be observed only when the Sun is below the horizon.