black, relatively stationary craft seen changing shape in windy skiesI work by a window facing east. The weather changed today from unseasonably hot to cool, so as the front moved in and storm clouds appeared, it became windy. I noticed a black, circular shape in the sky that remained stationary for 20 or more seconds, so it caught my eye. My first impression was that the object might be a rather large balloon within a half mile of my position, but oddly it remained stationary in the wind. I put my caller on hold and looked more closely. After remaining stationary for about 30 seconds, it began to move slighly, in almost a fluttering way or jagged way, suddenly dipping to the left and downward, and changing shape from circular to more flat. Then it went up again and a little to the right, again becoming more circular, but also changing shape so that it was periodically circular and then more ovoid. It headed back to the left and would remain somewhat stationary and then dip further down. At this point, as it got lower, I could see that there was a lighter colour on top, almost like the reflection of a dome (there was very little sunlight "behind" my position, peeking through stormy clouds). With that extra shading, the object looked more saucer-shaped. There is a shopping mall next to my office and as I watched the object, it dipped down until it disappeared just on the other side of the mall. If that were the case, the object must have been within a half-mile to a mile of me, and smaller than a helicopter, but much larger than a bird. It definitely appeared to be under intelligent control under windy conditions, and the changing shape was also quite dramatic.