Observed a strange circular spotlight on ground in rural area

I was on my way to work, driving along a rural route between Conesus Lake and Geneseo, NY. That area is pretty much all farm country, and at the time there was at least 8" of snow on the ground from a previous snowfall. The night was clear and very cold...around 20 degrees Fahrenheit. 
I came to a stop at a remote four-way intersection, and sat at the intersection, and carefully looked both ways for traffic. While looking to the left, a circular light suddenly appeared on the snow, as if someone was shining a spotlight straight down. The light was approx. 30 feet in diameter, and was about 150 feet from my position. 
There were no houses in the immediate area, and there was no sound being made. I was driving my winter car, an old Camaro, and the curvature of the window restricted me from looking up to see the source of the light, and the window handle was broken, so I couldn't roll the window down in order to put my head outside to get a better view.  
At this point I sensed that something very strange was happening, and pretty much floored the accelerator to exit the area as fast as possible.  
When I got to work, I was relating the incident to a few of my co-workers, when another worker (an off-duty policeman) arrived and announced that his police radio was bristling with reports of strange lights and ufo's all over the region.
Witness indicates that the date of the sighting is approximate.  PD