Dense Fog in Grand Canyon Country, Arizona

The ASOS at the Grand Canyon Airport reported dense fog between 900 PM and 200 AM.

Widespread light to moderate rain (over two inches in places) over a two day period (December 4-5) was followed by a large area of high pressure. This created inversions that lead to the widespread development of fog and often dense fog. The time of dense fog development and dissipation was difficult to forecast and record. The entire Grand Canyon was filled with low clouds at times while the Grand Canyon Airport 7 miles away was clear. Some ASOS locations were under low clouds while fog impacted highways and freeways just a few miles away.