Large disc-shaped UFO over Hamburg, NY

On May 30, 2015, at 9:10 PM, an inhabitant of Hamburg (Eerie County, New York) has witnessed on NUFORC website to have seen a large and black flying saucer in the sky. What is it?

Witness report:

Large black saucer shaped object moving very slow from north to slow, flying extremely slow. Silent and flying very low. Smooth could see no distinctive features. White streaks were seen in a straight line coming out the side of the craft. The craft followed the direction of the streaks. Was traveling from west to east and about the time it was to the treeline from my view it turned south. It almost appeared to be a very large balloon by the way it was traveling. Smaller than a blimp but much larger than a hot air balloon. Realized it wasn't a balloon when it emitted what looked like a white streak from its side and moved in the direction of the streaks projection. If it was a type of thruster it should have went the opposite direction of the streak but it precisely turned and followed the direction of the streak almost instantly. We have never seen anything like in our lives and I am very skeptical of the ufo topic. I have no Idea what this craft could have ! been and I'm still in amazement as to what we saw. Hoping others have seen it and maybe took video. Would love to see this on the local news and get some kind of explanation as to what it was or if its truly something unknown.

Photo: Skyline of Hamburg, New York (Pudbog / Wikimedia)