Question

What are the most rare cloud formations?​

Answer 1

Answer:

One of the rarest and most fleeting formations, this cartoon-like breaking wave is the Holy Grail for many cloud-spotters. It occurs almost everywhere in the world and at all levels of the atmosphere. But it only lasts a few minutes before dispersing without a trace.

Answer 2

Answer:

• Nacreous clouds.
• Arcus.
• Virga.
• Mackerel Sky.
• Mammatus.
• Fallstreak holes.