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.They have iridescent colours but are higher and much rarer than ordinary iridescent clouds. They are seen mostly but not exclusively in polar regions and in winter at high latitudes, Scandinavia, Alaska, Northern Canada.




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.




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. Noctilucent clouds appear to be luminous yet they reflect the sunlight from the other side of the earth at night, giving them a glowing appearance.




Mushroom Clouds - A mushroom cloud is a distinctive mushroom-shaped cloud of smoke, condensed water vapor, or debris resulting from a very large explosion. They are most commonly associated with nuclear explosions, but any sufficiently large blast will produce the same sort of effect. Volcano eruptions and impact events can produce natural mushroom clouds.




Shelf Clouds - A shelf cloud is a low, horizontal wedge-shaped arcus cloud, associated with a thunderstorm gust front . Unlike a roll cloud, a shelf cloud is attached to the base of the parent cloud above it (usually a thunderstorm). Rising cloud motion often can be seen in the leading part of the shelf cloud, while the underside often appears turbulent, boiling, and wind-torn.





Roll Clouds - A roll cloud is a low, horizontal tube-shaped arcus cloud associated with a thunderstorm gust front, or sometimes a cold front. Roll clouds can also be a sign of possible microburst activity. Cool air sinking air from a storm cloud’s downdraft spreads out across the surface with the leading edge called a gust front. This outflow undercuts warm air being drawn into the storm’s updraft. As the cool air lifts the warm moist air water condenses creating cloud, which often rolls with the different winds above and below