Pogonip

Pogonip \POG-uh-nip\ , noun;
1. An ice fog that forms in the mountain valleys of the western U.S.

Great word today because.....IT'S SNOWING!!!!
Yes, yes, it snowed in the Midwest days ago, but it has finally come to the Big Apple!

I can't find this word in the online Oxford English Dictionary, but according to Wikipedia (not the best source, I know, but the only one I have at the moment):
Pogonip is an English adaptation of the Shoshone word payinppih ("cloud"). It's a phenomenon that only occurs under specific conditions where humidity is nearly 100% and the air temperature is well below 0°.

This makes me think of that myth that the Inuit language has a hundred words for snow. That idea arose out of a misunderstanding by the first wave of Europeans who encountered the Inuit people. In reality their language is like German in the sense that they have long compound words with complex meanings, so something like "drifting snow" in English would probably be compounded in Inuit and look like one word, but it isn't really. There was also a tendency to romanticize this idea of a ridiculous amount of snow words, so the equivalent of something like "water = melted snow" or "rain = unfrozen falling snow" may have been included in these word lists even though they are a bit silly.

*Today's word and the first definition were both taken from Dictionary.com's 'Word of the Day' for Monday, December 6