Heather (that's her over there...isn't she cute?!) has asked an excellent question.
This time of year in Michigan, we get snow warnings, watches, showers and "squalls." And it often changes every day .
Snow Squalls are much more dangerous than snow showers. Initially because they are defined as "a brief very intense snow storm with heavy winds and near whiteout conditions." All of those things together make this quite a trecherous condition. A squall also seems to come out of absolutely nowhere, whereas with a snow shower you can see it coming and also still see through the snow--visibility is not so limited. There may even still be blue sky suring a snow squall, but because of the intensity of the wind and snow, you wouldn't ever know it.
The other reason that squalls are so stinkin' dangerous is that once the snow starts falling, people freak out and forget that they have anti-lock brakes, that there are other drivers on the road, and that they will loose control quickly and plow right into the snow bank. Or into another car. Crazy Michigan drivers. You'd think we would have learned by now...