I was walking into the BARC (where I have my office and lab) after lunch the other day, when I came upon this scene:
A closer look:
Who put them there, or why, we do not know. But there they were and are.
Last night, hoarfrost started building up on things. By this afternoon, my car was covered in it. Hoarfrost can be amazing, with long fern-like feathers growing off of surfaces.
The best was the spiral effect the frost that grew on the antenna made.
Out of Ice and Time 
Wow. That hoarfrost is beautiful—in a “I’m glad I’m not actually there” kind of way! We just had our coldest night of the winter. It was 19F when I got up this morning.
I cannot imagine working (or living) in such a climate. I can, however, imagine a number of novels (and genres) being based on it!
The problem with hoarfrost is that it must be foggy for it to happen. That means gray, dreary days. 😦 the flags are cool, sounds like a mystery to be solved!
Great photos of the hoar frost!