My partner and I were sitting on our enclosed balcony watching a thunder/lightning storm. At this point the storm had been dying down, and lightning would strike every 1-3 minutes, with rumbling thunder about 10 seconds after each strike. The rain was steadily coming down, but not a downpour. By this time storm had been going on for about 30 minutes.
Suddenly I saw two very large yellow-amber lights and a smaller, pulsing red light between them coming through the dense clouds in the distance. It was coming from the general direction of the airport, so my first thought was that it was an airplane. This is when I pointed the lights out to my partner (he was facing the opposite direction). But then I realized that no commercial plane would take off during this weather. Judging from the size of the lights, I thought it could be a cargo plane, as we live about 20 miles from the Niagara Air Force Base, but my partner said that cargo planes have 4 yellow lights, and these were distinctly two very large lights. Also, the lights were moving much more slowly than a plane would.
As the lights got closer I saw that the red light was in between but slightly behind the two yellow lights. It was a bit more than half the size of the yellow ones, and it was slowly pulsing. I would say that the light was solid red for two seconds before going dim, and it was totally out for about one second. It was not making any noise-- if we had been inside we never would have known it was there. My partner said he saw it teetering slightly but I did not notice this. The lights were in our line of sight for about 1-2 minutes total.
As it got closed we noticed that the lights appeared to be connected, rather than being on wings of an aircraft. They passed directly overhead and we made out what appeared to be a triangle-like object, but the surface was very dull. We do not recall seeing a third yellow light. Right before it went over our building and we lost sight of it, each yellow light was approximately the size of the diameter of a AAA battery. When it went overhead it didn't seem too close to the surface, but it was certainly closer to the ground than any airplane I have ever seen (that was not in the process of landing). It still did not make any noise
Normally we would have rushed outside to keep observing it but we didn't. I guess it was because of the weather, but we also were in such shock and awe that we couldn't move. Both of us had our iPhones with us, and during the sighting neither of us even thought to take any video.
Just as a side note, we have 4 cats and a dog, and none of them seemed to be acting out of the ordinary. All of our lights were out so we did not see any electrical activity.