A rare ground inversion last Thursday filled the Grand Canyon from rim to rim with a sea of clouds.
Ground inversions at Grand Canyon are a sight to behold – clouds fill the canyon with sunny, blue skies above the rims. The topography of Grand Canyon enhances the effect of inversions, creating the dramatic views of a sea of fog and clouds seemingly dense enough to walk out on.
Ground inversions occur when cold air is trapped by a layer of warm air. On clear, cold nights ground temperatures cool rapidly. Air in contact with cold surfaces cools and sinks. At Grand Canyon cold, moist air drops into the canyon forming cascading “waterfalls” of clouds pouring down the rim filling the canyon. Warm air above the rim holds the clouds in place until enough solar radiation is received to warm the surface of the rocks, heating the cold, dense clouds in the canyon and causing them to rise.
Visitors at Grand Canyon during an inversion are challenged to be patient. Waiting out the warming process is well worth the effort; when the clouds start to lift the currents of air swirl and turn on themselves parting like curtains to reveal bursts of color and light, a breathtaking spectacle.
Below is a one minute time-lapse video from the Grand Canyon National Park showing what happened last Thursday: