Overcast clouds change into hexagon, then sunshine, and a very large and fast flying saucer.

While driving westbound on NY's Northernstate parkway, I noticed suinshine on an overcast day, i looked up to see clouds swirling and forming a hexagonal shape of clear sky, what looked to be much larger then a 747 airplane started darting back and fourth in the sky, at times going out of my visual range. The thing looked like a steryotypical flying saucer though with a less narrow and taller top half, almost shaped like a fedora styled hat, and appeared a dark grey indistinct color. The thing was very huge, I cant understate this, if I had to estimate, I would say roughly 300' across maybe 40' tall. The thing was moving to me what looked like left and right but was probably closer to North / south given my orientation. The thing was moving incredibly quickly i would guess at least a few miles as it moving beyond my ability to see it, also the trees by the side of the road were tall, I could only really see to my left/up, but i could see clearly for a fair distance given the curve of the road. After going left / right a few times maybe less then 10, it was gone, and the clouds were back to normal as well. the geometric vortex in the clouds seemed to follow it and give a clear view of it as it moved. I was driving in moderate traffic at the time so I had maybe 15 seconds of view time over a maybe 30 second period.
I didn't know I could report this until today, the dates and times are estimated as it was a while ago, but I'm fairly certain the location is within 2 miles of the sighting.