20 to 30 black objects hoering in sky

October 8, 2015, At approximately 10:05 AM my husband and myself were driving west on Hwy 180 and between Fowler Ave and Clovis Ave I noticed, I thought a flock of birds in the right hand sky above the tree line.  I said "look at that flock of birds or maybe it's ducks."   My husband responded "that can't be birds, they're too big for birds."  The formation was kind of round to the left and gradually & sparsely dwindling to the right, kind of like the tail.  The formation was made up of black shapes, some large, some larger and some smaller.  Their shapes were bigger on one rounded end than the other rounded end and the sides were straight lines.  Some of these shapes were moving and the smaller ones in the tail section were fading.
So, right before Clovis Ave, the winery storage tanks cut off their view until you're almost under the overpass.  At that point the sky opened up again and the shapes converged into a larger mass (left) that still had the shapes, but they now were much darker and they were NOT moving, but kind of hovering in the air (the tail, for lack of a better word, had disappeared).  It is hard to describe in words, but easier to describe verbally.  I think it was kind of hard to look at, meaning hard to describe something that made "no sense!"  
They disappeared again because of the freeway embankment, but my husband said we'll catch them at Hwy 41 where the road climbs and the embankment disappears.  Well, needless to say, the mysterious "thing" in the sky had disappeared!