Fallstreak hole
- Cirrus Ci
- Cirrocumulus Cc
- Cs cirrostratus
- Altocumulus Ac
- Alto Stratus Ace
- Stratocumulus Sc
- Stratus St
- Cu Cumulus
- Cumulonimbus Cb
- Calvus cal
- Capillatus cap
- Castellanus cas
- Congestus con
- Fibratus fib
- Floccus flo
- Fractus fra
- Humilis hum
- Lenticularis len
- Mediocris med
- Nebulosus neb
- Spissatus spi
- Stratiformis st
- Uncinus unc
- Duplicatus you
- Intortus in
- Lacunosus la
- Opacus op
- Perlucidus pe
- Radiatus ra
- Translucidus tr
- Undulatus un
- Vertebratus ve
Special shapes
- Arcus ar
- Incus in
- Mom ma
- Pannus pa
- Pileus pi
- Tuba tu
- Velum ve
A Hole Punch Cloud ( from English- hole punch = Locher, also Punch Hole Cloud and Fallstreak Hole) is a relatively rare to be observed weather phenomenon and describes a compact cloud with bizarre peaks, which are characterized by a distinct circular to oval space of the surrounding clouds - mostly altocumulus, rare Cirrocumulus or stratocumulus - settles.
Theories on the development of cloud holes
The exact cause of leading to the formation of the cloud is not yet understood. It is believed that it is caused by rapidly falling ice crystals. Aircraft as the cause can not be excluded.
The ice crystals falling originate either from a higher cloud or they were produced by the engines of aircraft flying over it. The falling ice crystals makes it possible to absorb water because the humidity binds to the ice. In the center of the cloud, it comes as they arise to snowfall, the cloud to grow and the cloud-free distance to the Altwolken is greater. The ice crystals grow at their sinking into deeper layers of the atmosphere and thereby deprive the ambient humidity. Arises in this way where this phenomenon occurs, a large gap in the cloud layer. Why the origin is local, has not yet been scientifically researched.
The ice crystals are due to the additional water intake increasingly heavier and fall faster towards the surface. If it takes long enough, because according to many falling ice crystals or large amounts of surrounding humidity is present, formed at the lower end of the Hole Punch Cloud from the fallstreaks a funnel-shaped structure, but that should not be confused with Tornado clouds. But the snow does not reach the earth because it is heated in the deeper layers of the atmosphere and melts or sublimates directly.