Regular followers of the blog will know of my aerodynamics background and the fascination I have with fluid flows. Anything that shows it off will pique my interest. The damp conditions that the Pacific Northwest offers can, if the light is nice, provide a good show on a plane that is configured for landing. Plenty of flap angle and low speeds will drop the pressure and condense the moisture. This Qatar Airways 777-300ER was coming over SODO on its was into SEA when I shot it. Plenty of moisture over the flap system and some conspicuous trailing vortices. Just the sort of thing this guy loves.