Black Sphere UFO hovering in storm Woodbridge GB 7/20/16

I was sat in the back garden watching a storm building when my attention was drawn to a spherical UFO high up in the sky, it was darker than the dark storm clouds behind it and changed color from gray to black, it caught my attention because it was stationary and was for several minutes as the storm built behind it. As I watched it moved eastwards very slowly and stopped on several occasions hovering in the sky. The UFO continued eastward and then turned and headed back into the storm disappearing into the clouds for approx. 2-3 minutes before appearing again at a lower altitude where again it hovered and appeared to be spinning, as I watched the UFO move slowly east again before stopping and then taking off at a terrific speed eastwards and ascended into the clouds before I lost sight of it. MUFON CMS# 77800