Reply To: Cavum cloud formation?

[Gregory Venarsky]

Hello Marcia,

I believe Cavum clouds form when the droplets in a layer of cloud suddenly freeze into ice crystals and begin to fall (causing the fallstreak to form). This can happen when ice crystals fall onto the cloud layer from a higher cirrus cloud and cause the water droplets to freeze. This can also happen when planes fly near or above the cloud and allow their fuel to fall onto the lower cloud and cause the water droplets to freeze. Great photos by the way!

Best Wishes,

Gregory V.