Michael Winter

USA TODAY

The Grand Canyon was a little grander Thursday in a very different, unusual way: It was fogged in. At least, if you were standing on the rim.

The rare climatic event was caused by what meteorologists call a temperature inversionThat happens at night when skies are clear, winds are calm and the ground rapidly loses heat stored during the day.

A cold, moist air mass settled into the canyon during the week, eventually creating a 500-foot-thick "low stratus deck" of clouds, said Brian Klimowski, meteorologist in charge at the National Weather Service office in Flagstaff, Ariz. With it came fog that hovered at the canyon rim or spilled over.

The canyon — 277 miles long, up to 18 miles wide and up to more than a mile deep — also filled with clouds and fog in November 2013, though the phenomenon usually happens only every few years.

"Almost looks like the tide coming in and going out," the Grand Canyon National Park staff wrote on its Facebook page.

"Rangers wait for years to see it. Word spread like wildfire and most ran to the rim to photograph it," a ranger wrote about last year's fog. "What a fantastic treat for all."

The view from the canyon floor would have been much different, Klimowski said. There was about 4,000 feet between the ground and the cloud cover.

Thursday's view was short lived. A cold front pushed into Arizona early Friday, clearing out the cloudscape. Strong wind, rain and several inches of snow were forecast through Saturday before the canyon resumes its familiar majesty.