In the movie Riddick, Riddick spent several months understanding environment and new life forms on a planet where he was left off. He used his vision to distinguish bad water from good one.
Later, after seeing the rain that was coming, he understands that it was bad news - for the creatures, which he fought earlier, it's a good environment for expansion. I don't understand how he gets this, it's somehow related to his vision.
How is it that Riddick knows the weather is bad news?