Black Clouds represent renewal and cleansing. They bring rain water that nuritouses the earth and lightning that causes cleansing in nature.
When the darkness comes we must look inward to find the light and have courage. To understand what we see in the darkness may not be real but only shadows.
This is the emotional part of ourselves, like the flowing water we must learn to go with the flow of life. The time of the West is when we learn that we are responsible to all things and to each other. We gather ourselves and family, working together to prepare for what is to come. Black symbolizes change from this life.