Attic insulation, very important

If you're in an area that just got some snow, watch your roof for the next few days.  If the snow on your roof melts before your neighbors, you may need more insulation in the floor of your attic, not in the roof rafters.  Why is that you ask?  Ever hear of ice dams?  What causes them?  What damage can they do to the wood of your attic?  Think of it this way.  If the snow melts from the heat in your attic, the water will run down the roof till it gets colder at night.  Then it will freeze under the snow.  Next day when it starts to melt again, it will start to back up under the singles, because the ice at the edge is still frozen.  This can cause damage to the wood under the singles.  So, if I'm correct, we want the snow to melt from the top of the mass, and run off into the gutters.  Any additions or corrections are greatly appreciated.  See photo below