BULLETIN: MORE SNOW ON THE WAY!
Extensive damage can happen in homes if ice damming occurs. Replacement of ceilings, walls and insulation can be very costly alone without considering carpeting, wood floors, furniture etc. Insurance will probably cover some of these costs but deductibles, replacement time, time off work, coordination hassles etc. will make it well worth the expense to prevent ice damming in the first place.
Fresh snow can be pulled off the edges of the roof with a roof rake, or snow rake. They are available at some of the local hardware stores. I have never found one at any of the "big-box" stores, but if the need is there I would not be surprised if they started carrying them. If you wait several days before you attempt to pull the snow off with a snow-rake you may have a more difficult time ahead of you. The snow may build up ice crystals and be very tough to remove.
With the expected accumulation of more snow the rest of the winter I would highly advise you MAKE THIS A HIGH PRIORITY! The added weight of all that snow on a roof can cause a collapse let alone water leaking into the ceiling and walls. This amount of snow this early in the winter could be still on the ground (and roof) until April.
PANTY-HOSE TRICK
If you have some old panty hose laying around the house you could fill them with "Ice Melt" (must be calcium chloride, not rock salt) and lay them vertical on the ice dam. The point is to make several vertical breaks through the ice dam so melted snow has a place to drain off the roof. This is a great trick but the best overall method is to remove the loose snow right away.
wire is attached to the lower sections of the roof and is manually plugged-in or turned-on by the home owner to heat up that part of the roof to melt off the ice and snow. These are somewhat inexpensive (relative to costly repairs or your insurance deductible) but should only be used as a last resort in correcting the ice dam problem. The heated wire does not have a long life and the underlying issue causing the ice damming is still unsolved. I would only recommend using heat tape if all other methods of correction have been used and the issue is still not solved for a particular problem area (may be related to tree cover, shading, wind direction, etc.)

