Hey! There's a Hole in My Cloud

As a follow-up to Sunday's nacreous cloud display, I was looking at cloud websites and came across something that I had not previously known about. They were pictures of what is called a fallstreak hole, also known as a hole punch cloud or a punch hole cloud. 'Rather fascinating' I thought and went on to other things.

Imagine my surprise when half an hour later, as I left the house, I looked up and there was a fallstreak hole almost overhead! Later in the day, two more passed overhead. Could they really be that common and I hadn't noticed them ever before?

I have no idea how common they are but this just had to be my blip for today - purely out of interest value.
The main cloud cover was a thin layer of altocumulus and persisted for most of the day.

Note on the formation of Fallstreak holes.

The cloud has to be formed of supercooled droplets of water in stable suspension in air well below freezing.
Something then triggers freezing at a point and then by some mechanism not fully understood the freezing spreads by a chain reaction through the neighbouring cloud. The ice crystals have a different aerodynamic and start to fall out of the cloud as virga. As they fall, they evaporate in the lower drier air.

Aircraft have been implicated in the triggering of many fallstreak holes.

This particular event seems to have three foci as there are three separate streaks of virga falling from the cloud.

Location: Kirkcaldy, Fife, Scotland