It is unlikely that we'll see much of a white Christmas.
We have a chance of snow through Friday morning but only a slight chance of light snow. At least dry weather will be easy on travelers. Unfortunately for snow lovers, we've already seen that winter sports have been postponed at area parks because there isn't any snow for sledding/tubing/skiing and temperatures are still pretty mild.
So far for the season, 3.9" of snow has fallen at South Bend Regional Airport. At this point last year we'd already seen nearly 25" of snow (24.8" total) from November and December and had 2" of snow on the ground on Christmas Day. Out of the last five years, we only had a white Christmas two of those years.
For the probability of a white Christmas anywhere in the U.S., we have a link to the National Weather Service: http://www.crh.noaa.gov/iwx/?n=christmasdaywx. This map is based on climate data and not on the current forecast so when you look at it, it shows the probability of seeing a white Christmas any year, not the forecast for this year.