One possible solution for ice dams is to install heat tape on the edge of your roof. It's more of a stop-gap measure, but heat tape can prevent ice from building up and doing damage to your structure. It's best to have it looked at when the weather warms up, and make sure the attic is properly insulated and ventilated, as mentioned in the previous post. You can buy heat tape or cable at a hardware or big box store. It installs with clips, so you don't need to use nails or penetrate the shingles in any way.