I've driven through some of the most dense fog in my entire life in the last few days.   It's been in the morning, on the way to work.  It's been bad enough over the hill that I've had to slow down to 15 mph to even see the lines on the road.   And every time, I think of Stephen King's 'The Mist.'

Have you seen it?  I would not recommend watching it until the suns comes out sometime later this week.