The thing I find hardest at night is to determine whether I'm in a snow shower only or in a cloud that's producing snow.
If I'm just in the snow, I don't worry too much. Maybe a little "impact snow", but nothing too severe. If it's in a cloud that's producing snow, I've seen negative icing to moderate icing.
-mini
PS
Along that topic. Anyone here fly the 727 that reported severe icing about 10 N of ILN last Monday night? Just wondering what y'all saw out there. I was on top by the time I got to that area, but it did have me concerned for a little bit.