Rare celestial phenomenon today engaged the attention of the inhabitants of northern Dalmatia, writes Crometeo.hr. In the layer of Altocumulus appeared a hole! It is a phenomenon that even today, even though we know that occurs, is causing a great deal of attention and amazement. Here’s the thing, like most similar phenomena, “fallstreak hole” does not yet have the appropriate Croatian translation. It is also known as the “hole punch cloud”. It almost always occurs in a layer of high clouds in the genus cumulus – Cirrocumulus or Altocumulus – and generally is circular or elliptical shape. The whole story starts with tiny water droplets in these clouds, which, despite the low temperatures, have not yet had frozen because they lack the core of nucleation, i.e. particles around which water drops to be able to crystallize. However, once you create crystals, water droplets quickly disappear domino effect in all directions and in the cloud create a hole. The crystals are falling down, which is often seen as a phenomenon like Virgil. Sometimes, as in the figure below that recorded by Claudia Bobanović.
These crystals rapidly “destroy” the surrounding water droplets in the cloud creating a hole, and the crystals themselves are falling down.