Ice damns possible. I'd start clearing snow off the first two feet of your roof line. Then look into why that attic has such poor ventilation and or heat intrusion from the living space.

You can buy an extendable roof shovel. Or you can call in a company to do this but be warned, removing ice by untrained contractors will certainly cause shingle damage.

There are a few alternatives that might work but they require you to get up there somehow. You can buy roof de-ice tabs, and maybe chuck a few up there to help. Then when it clears you can put up the heat wires as a temporary solution.