Park rangers can wait years to see a weather event like the one that occurred last week at Grand Canyon National Park.
CNN Meteorologist Brandon Miller said cold fog trapped in the canyon by a "lid" of warm air produced what's known as an inversion. The result looks something like a river of clouds flowing through the canyon, obscuring views of the canyon's depths.
While inversions themselves are not rare, Miller said what made this event unique was the sunny skies that accentuated the layers of air. Normally, he said, inversions lead to a "mucky view" such as one might see when driving through heavy fog.
"Snow had fallen in the area beforehand and was beginning to melt," said CNN Meteorologist Chad Meyers. "The melting snow created a cold layer near the surface. Think of opening your freezer and watching the cold air 'fog' falling to the floor. This cold air (because it is heavier than warm air) sunk into the canyon and created the fog."
Over Thanksgiving weekend, park officials say two inversions occurred. One on Friday, the second on Sunday.
The inversion lasts until air temperatures are warm enough to allow the fog to dissipate, Miller said.
Officials at the park posted some stunning photos to Facebook and Instagram of the weather events, which received thousands of views and comments.
"I was there!" posted Tim Zeko on the Facebook page. "First trip to the Canyon. Unbelievable."
What is the most beautiful weather event you've witnessed? To see more of the photos, visit the Grand Canyon National Park Facebook page.