Amazing meteorological phenomenon: Fallstreak hole, a circular gap that appears in the clouds

fallstreak hole

It is undeniable! Nature never ceases to impress us. Sometimes by its indescribable beauty and sometimes by its immeasurable power. Let’s admire another amazing natural phenomenon; the fallstreak hole.

A fallstreak hole is defined as an incredible natural marvel where a large elliptical gap appears in altocumulus clouds. Also known as a cavum or a hole punch cloud, it is formed when part of the cloud layer forms tiny droplets of water that are beyond freezing point but remains liquid.

These droplets will not freeze unless they have a reason to solidify. For instance, which is in most cases, a plane passing through the cloud layer can encourage the cloud droplets to turn to ice crystals. When the ice crystals are large enough, they fall as a ‘fallstreak’, leaving behind a hole which expand outward as other droplets start to freeze.

Scientists have been studying this beautiful cloud effect and concluded that the freezing water might cause a hole to expand outwards from the point where the plane flew through the cloud. When the water droplets change from the liquid to the solid state, they slightly emit heat that is enough to cause the air to expand and rise a bit, causing the surrounding air to fall. This causes the evaporation of the water droplets.

According to scientists this is the process by which the fallstreak of ice crystals produced by the plane’s movement through the cloud layer creating a circular hole.

As a reminder, the fallestreak hole was observed among others in New Zealand, Florida and over Sacramento, California, US.