Above-Anvil Cirrus Plume (AACP) billows up above the top of the storm clouds and head downwind, acting as a sort of early warning system for extreme weather events.
For the first time, scientists think they’ve figured out what causes these cloudy plumes. What are known as hydraulic jumps – also seen when a waterfall crashes into the still water below creating a foamy cloud – are created as air rises above and then falls back into the thunderstorm clouds.
https://www.sciencealert.com/we-finally-know-why-icy-plumes-flare-ahead-of-deadly-supercell-storms
