Is This Cumulus Or Nimbus?

One look at those clouds yesterday and I was thinking a storm cellar might be a good thing to have.



The blue sky was quickly being elbowed out by those big raging bullies.



When I reached the supermarket parking lot I was adding emergency flashlights and water to my list.



By the time I returned home the blue sky had regained control.



Perhaps it's time to do some serious learning about clouds and their meaning.