Roger's SkyPix

Visual Effects

Anvil Shadowing Altocumulus

Anvil Shadowing Altocumulus

A small patch of altocumulus is bisected by an anvil shadow from a supercell. The Ac was moving rapidly from sunlight into shadow, which was SSW-NNE. Storm observers can use cloud motions at different levels to get a rough idea about the wind shear. In this case, I could tell there was good shear from the eastward spreading of the high anvil, the SSW-NNE Ac motion, and some low fractocumulus (unseen) near the storm base moving toward the NNW into the storm. Thinking in 3D, this implies strong veering and some speed shear with height -- good support for rotating storms. The whole scene made for a great real-life laboratory on severe storm environments; and the shadowed AC was a fascinating distraction from viewing a wall cloud (unseen) dangling beneath the storm's base. [This storm's wall cloud later evolved into one of the most spectacular I have seen.]

Anton TX (9 Jun 97) , looking overhead-SW