The mild winter cool of a late Friday, December evening suddenly turned bitterly cold as temperatures dropped from the 50s to the single digits in under an hour.

A fog rolled in with the bitter cold and, as it froze, it stuck to anything it could cling.

In the early morning light of the last Saturday of December, the city of Cheyenne looked as if a gentle snow had fallen overnight.

But it was not snow clinging to the branches and frozen blades of grass. It was...

Okay at this point we have a bit of a problem. See, the name of this weather phenomena sounds like a bad word. People are so easily offended in this day and ages we don't like to take chances. We like to think of ourselves as a family company. So we don't really want to say it out loud.

I'm sure you would like an explanation, so, here it goes: It is called Hoarfrost. Pronounced the same as the more familiar "whore."

So as not to offend we shall, from this point on, refer to this weather event as "Lady Of The Evening Frost."

While it looks very much like snow Lady Of The Evening Frost is freezing fog.

Moisture in the air brings the interlocking crystal patterns of frost together, building up on tree branches, signs, fences, anything it can stick to.

With a light wind, it will accumulate on the downwind side of objects.

My local photographer friend Tim Mandese took pictures as I dove us around in the early morning light. We had no idea Ladies Of The Evening frost could be so beautiful.