Alien And Dangerous
A cloud is just a cloud, right? And most of them don't have too strong an effect on us. Oh yeah, Seasonal Affective Disorder is a thing, but subtle enough that it goes un-diagnosed all too often.
But I digress.
Some clouds, they seem... not of this earth. So when you see that kind of trouble brewing... get the kids to shelter, secure any loose items, and get ready to weather one hell of a storm.