Pyrocumulonimbus

Start on blocky column to large detached flake in corner, felt solid. Wind up through either corner to anchor. Difficult and suspect protection. GUOS.

The pyrocumulonimbus cloud (pyroCb) is a type of cumulus cloud formed above a source of heat such as a wildfire and may sometimes even extinguish the fire that formed it. It is the most extreme manifestation of pyrocumulus. According to the American Meteorological Society’s Glossary of Meteorology, a pyrocumulus is "a cumulus cloud formed by a rising thermal from a fire, or enhanced by buoyant plume emissions from an industrial combustion process.". Unreal example was visible over Los Alamos due to the Las Conchas plume.

Left of Smoke Signals

Standard rack.