How much snow?

How much snow can a TC roof safely handle? It has been snowing since 6am here in Topeka and hasn't let up yet. There's more than 10" on the ground with a possibility of 2" more on top of that before it moves out of here. I haven't seen this much snow since I bought my rig two years ago and was wondering how much snow can accumulate on top of the camper without causing harm. I'm not going out at this time of night to clear snow off the roof and will do it first thing in the morning.