The tactics will depend on the amount of snow, snow type, temperature, and terrain. Generally maneuvering is most hampered when the snowfall is at shin-level or above. Neither party will be able to run as fast or dodge and move away quickly as your legs get bogged down working through the snow. So obviously with lower the snow levels, more speed can be obtained more quickly. However, snow can also be insanely slick if only as high as a shoe-sole. Not to say that someone won't be able to sprint through foot deep snow, it will just take longer to get moving, and get used to moving through that kind of snow. If they are making a new path then they can be followed down it. Sidewalks, parking lots, and central plazas will have a tenancy to be the most cleared parts of the map; so yes, places where people normally walk and enjoy themselves. However, depending on the length of time that the snow has been there, they can rather easily to psuedo ice-rinks if they haven't been sanded(sometimes even if they have been if one is going fast enough), or more often, just after they have been scrapped off. Parking lots and roads can suffer from this as well because traffic will cause the snow to compact to ice. This can be advantageous to either party as a human rushing to change direction can slip just as easily as a zombie having to dodge around a stunned comrade. [These happened to a zombified friend of mine twice(trip up of maneuvering), and me as a human once(zombie getting past another one). Once a human was being chased into a building, the zombified friend walked out and the human slipped and fell on their bum and my friend tagged them.] As well, this ice-rink like state can be used to increase range for a slide tackle dodge for zombies, but that means the slider spends more time on the ground, and more likely to be targeted again.
I have more experience with dry snow than wet snow, so expect some variation depending on the region and local climate. If going through a wet snow drift, players will(likely) get more water in their shoes than if they had gone into a lake. Wet snow will also likely be less viscous(the water lets it run more easily) and let one slide further and slip around more. Dry snow is a little easier to sled down, but both can bog up rather quickly if steps are not taken(pun intended). As well, dry snow will be less of a wetness problem until the player gets back inside from the snow and finds it all melting. As well, whatever snow there is (found with dry snow) tends to be crunchy, in other words, noisy. This makes it harder to move quietly as there is always a chance that someone will hear you. For this there are two options, stay still and wait for an ambush, or rush and hope that another zombie sees the human and tries to rush as well. For humans this means that no matter how much cover you have concealing you, if a zombie is in the area, they will likely hear you. And on any dry or compacted ground, if there is gravel in your boots, if there is a big enough piece, it will sound off as you walk.
Temperature is critical as it will affect the capability of the weaponry used, except for socks of course. Blasters are more prone to jamming at colder temperatures as the plastic and metal deform slightly at different rates. Older models may lose a significant amount of power if out in the cold for an extended period of time(such as going on a human mission or patrol). Even the darts will act up, stiffening in relation to the cold. This happened most with a Rampage that I was borrowing. And I have heard/seen/experienced horror stories where this has caused misfires with the Stryfe and other blasters using the same firing mechanism when the trigger pull wasn't fully committed. Of course all of this happened outside at a play temperature of about -10 F to -15 F with ±5 degrees variance. At night this can be especially prevalent as temperatures get colder.
The general terrain will also shape the battlefield in addition to the snow. Snow covers virtually everything up, including that space that is covered in decorative rocks and that little foot high ledge that you like to jump down over the summer. They are still there and one would do well to remember them if they wanted to make a new path. Snow can also form its own terrain in the form of snowdrift, giving either side an advantage of another obstacle to go around and hide behind. As well, going downhill through fresh snow can be much more controlled as the snow absorbs a fair amount of impact. But still go downhill facing the direction you want to go. On the other hand though, going uphill through fresh snow will be that much more of a nightmare as both gravity and the snow are against the player. Still, the main point of this part is that the snow covers various terrain features up, so be careful. After talking to another player about suggested tactics, they mentioned that deep snow can be used to slow zombies down if you are willing to wade into it. As well, less dedicated players probably won't follow you.
*Notes: I do not mean to be a thread necro, but I live in an environment that gets very cold and hangs on to snow like no other, so this topic is of interest to me. This seemed early enough that it wouldn't be too much of a bother to store all the knowledge in one place as well because the topic is being relatively recently talked about. All of this is based on my personal experience playing out in the cold. The first three days of the game, mother nature had decided to hit us with a blizzard. The entire game was played in snow. Here
is a Facebook album for anyone interested, it is an escort mission.Edit:
Next post I will discuss tactic use and how tactics that were used were modified for the snow. This post was important because I believe that climate and terrain are important parts of formulating effective tactics. Though this was our first year with the game, so our tactics are probably haphazardly formed to fit the situation.Edit #2:
Added tidbits to all of this now that I am actually in winter again and am noticing how the snow effects movement.Edit #3
Grammar and clarification, info concerning ice on roads