Sunday at the California International Airshow(CIAS) the air's moisture content was near maximum as the marine layer hovered just north of the show. As the day progressed, the airshow shifted from blue sky to low clouds. Most performers performed low shows as the weather deteriorated. The Super Hornet did the low show and really wowed the crowd with constant vapor clouds surrounding the aircraft.
http://www.kbvp.com/extreme-videos/f-18f-super-hornet-maximum-shockwave-vapor