Last year, the Grand Canyon National Park Facebook page described a rare total cloud inversion as "a once in a lifetime, outstanding, crazy, amazing, mind blowing inversion."

Challenging that 'once in a lifetime' bit, it happened again this week.

This time, the park service managed to capture a stunning timelapse of Thursday's event, showing the 'sea of clouds' in all its glory. The video shows 15 minutes of the phenomenon condensed into one minute:

A 'temperature inversion' sees fog and cool air 'sealed' in the canyon by warm air. It typically happens around once or twice a year at the Grand Canyon.

However, a 'full inversion' is a much rarer treat, traditionally only occurring once or twice a decade. It's the sort of phenomenon that even park rangers might not experience over years spent working in and around the canyon.