Along (sorta) the same lines...
I read this a good while back:
What if a rainstorm dropped all of its water in a single giant drop?
Their storm is 100km to a side. Their storm has a TPW (total precipitable water) content of 6cm. The water in their storm weighs 600,000,000 tons.
And then they hypothesize what would happen if it fell as one giant raindrop.