Some folks in Colorado were treated to a rare sight on Thursday morning.

Known as either a “white rainbow” or “fog bow,” this meteorological phenomenon occurs when sunlight shines through water droplets, according to

There was dense fog in parts of the state for the morning commute. Since fog droplets are smaller than rain droplets, much of the color from an actual rainbow is lost, giving “fog bows” the white appearance.

According to NASA, a fog bow shape is visible when the sun is behind the photographer.

The fog itself isn’t confined to the arch, but it looks like way if the person who sees it is at just the right angle.

Here's a fog bow spotted in Loveland courtesy viewer Craig Stenger.


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