When a cloud appears to "fall" from the sky, it isn't the entire cloud plummeting downward, but rather a part of the cloud that is falling. This phenomenon is commonly associated with a fallstreak hole.
Understanding Fallstreak Holes
Fallstreak holes, also sometimes known as punch hole clouds, aren't actually instances of a whole cloud falling. They are formed when a section of a mid-level cloud, such as altocumulus clouds, experiences a disturbance.
Causes of Fallstreak Holes
- Warm Air Pockets: Warmer air beneath the cloud layer can create a less dense area. This warmer air can cause ice crystals within the cloud to evaporate and fall as precipitation.
- Object Disturbance: When an object, such as an airplane, passes through the cloud, it can create a disturbance that triggers the precipitation process. This disruption causes the supercooled water droplets to freeze and fall out, creating the hole-like appearance.
The Falling Effect
The "falling" appearance is actually the result of ice crystals and/or water droplets within the cloud falling out of the cloud layer. This precipitation leaves behind a clear gap in the cloud, which we perceive as a hole with a visible fall streak.
Table Summarizing Fallstreak Holes
| Feature | Description |
|---|---|
| Type of Cloud | Typically occurs in mid-level clouds like altocumulus. |
| Appearance | Looks like a hole or gap in the cloud layer, often with visible precipitation falling out of it. |
| Causes | Warmer air pockets below the cloud layer or an object, such as an airplane, passing through the cloud layer and disturbing the supercooled water droplets. |
| "Falling" | The visual effect of ice crystals or water droplets precipitating out of the cloud, not the cloud itself falling. |
In summary, when a cloud appears to fall, it's actually a part of the cloud—often due to a fallstreak hole—where ice crystals and water droplets are falling out, creating a visible gap.
