I can’t tell what it is, but I don’t think is a fallstreak hole. In a fallstreak hole, the ice crystals that form tend to precipitate and evaporate, so upper part is thicker and the lower part is fading away, like in a virga. Here it seems that the falling stuff coalesces in one long thick cloud. Unless, it’s the other way around, where the “ribs” are actually going down, but to me their curvature indicates that they are going away and up.
Jean-Pierre, do you have other shots of this phenom, either other angles or how it evolved in time, before and after?
