Ice dams occur when temperatures are low and there are a few inches of snow on the roof. The only way to make it stop is by removing the ice and giving the water a place to flow safely off the roof.
It is extraordinarily dangerous work, so if you are going to do it on your own please wait until you can get a friend to help.
You can also hire a roofing contractor to do the work for you.
The right weather conditions for ice dams is usually when outside air temperatures are in the low 20s (°F) for several days with several inches of snow on the roof.
When the snow and ice are gone you can call me to inspect for any damage.