I would say that you MIGHT be able to, but it might be risky. Just either shovel it or make sure you check that the area where you would be jumping is safe and not icy. I personally wouldn't do it, but that is just me. You probably could if you checked the ground COMPLETELY.
I would even b cautious riding in snow because you don't know if there is ice underneath and if you do jump....I would definitely check the ground and stick to just the basics and low jumps maybe 2 ft...and that's if your horse is really confident and NOT green
I don't have a problem riding in the snow. I do it all of the time. As long as you're not out there galloping around like a lunatic and you are aware of your surroundings you are fine. You need to be cautious, but I have always ridden in the snow.