http://www.accuweather.com/en/us/buffalo-ny/14202/october-weather/349726
I don't remember, and haven't been able to find a weather report from 4 days ago, so the precise reason for that cold snap escapes me, but it hit a significant part of the North-East US and perhaps a bit more than that.
Generally when wind blows in from the North, we get cold air, so that's probably about what happened. The great lakes probably kept Buffalo slightly warmer during that period, not colder cause the late water was probably warmer than the air temperature.
This article is somewhat related, though I'm not sure how well it applies to the dates I think you're talking about.