Roger's SkyPix

Mini Cloud Atlas

Volcanic Pyrocumulus

Volcanic Pyrocumulus

During a prolonged steam eruption, Mount Saint Helens crowned itself with a ragged cumulus cloud for just a few minutes. Heat and moisture from the steam helped to form the pyrocumulus, where the air mass previously had been just a little too stable and/or dry. This shot came just a few minutes after a zoomed view of the plume and a rock fall down the left (NE) side of the lava dome. The pyrocu came and went quickly, as increasing horizontal winds advected drier air atop the steam column once again.

14 NNE Cougar WA (11 Jul 6) Looking SSE