Icy fog

I have encountered a lot of weather, having lived in the Northeast my entire life, but I don't think that I have ever before encountered conditions where it was 8 degrees Fahrenheit, cloudy, and foggy. As I drove down the road this morning, there was a low, thick fog in the stream valley, and more down by the river. Very odd. Not sure how that could have happened. Believe it or not, I have actual meteorologists in my employ, so I could have asked what the heck was going on. Perhaps I'll demand a memo.