Hiya again.
The closest areas where it is more likely to see snow are Niseko, Kiroro and Daisetsuzan.
Niseko and Kiroro are both popular skiing resorts near not so far from Sapporo.
Don't forget that even in Niseko and Kiroro, ski slopes usually will open in late November (it's about two or three weeks later than when you will visit there) Last year, the Kiroro Snow World (ski slope's name) was open for public use on the 25th of November.
Daisetsuzan mountains are located in the central part of Hokkaido; People visiting the Daisetsuzan mountains usually stay at a hot spring inn at the foot of the mountains to see the top of the mountains covered with snow.
Anyway, it is highly unlikely that you will see snowfall in Sapporo then (If you definitely want to see snow, I recommend you to visit Sapporo in or after late December, or go to a hot spring in the Daisetsuzan mountains)
Here is a YouTube video showing a way at the foot of the Daisetuzan mountains in early November 2005:
http://www.youtube.com/watch?v=jZjyMY3EEnEAs you see, in the case of early November 2005, still no snow there.
Here is a YouTube video showing Sapporo in early November 2011:
http://www.youtube.com/watch?v=6Xpk-hvKcG4Can you see any snow?
Also, take a look at another YouTube video. This is a scene of Sapporo city on January 7, 2011:
http://www.youtube.com/watch?v=kH6ayzfTLJkAs you see, very bad weather and heavy snowfall.