What a difference a year makes as far as who will see a white Christmas this year compared to last year!

In 2010, approximately 50 percent of the country had a white Christmas, much more than is expected this year. Currently, only about 25 percent of the country has snow on the ground.

To the pleasure of some and dismay of others, some of the big Midwestern cities that had a white Christmas last year are not as likely to have one this year. Chicago, Indianapolis, Detroit and St. Louis are all included.

The NOHRSC snow analyses for Dec. 25, 2010, last Christmas, shows that approximately 50 percent of the U.S. was covered by snow.

Some snow will even brush Chicago and Detroit early next week, but it is questionable whether enough cold air will stay put for snowcover to remain through Christmas Day. A lack of lasting cold shots is a theme of this season so far.

“Colder air was much more established across much of the country last year,” according to Expert Senior Meteorologist Bernie Rayno.

From Dec. 1 to Dec. 25, 2010, many cities had temperature departures well below normal. The following is a list of approximate temperature departures from normal (in degrees F) during that time period: Bismarck, N.D., -6; Minneapolis, -5; Chicago, -7; Cincinnati, -10; Pittsburgh, -8; New York City, -5.

Even areas farther south and east, such as Cincinnati, Louisville and Nashville, had a white Christmas in 2010. However, a white Christmas for these cities is doubtful this year.

“The second factor to the difference in snowcover this year compared to last is the storm track. There were a lot more storm systems that came out of the Plain states,” said Rayno.

“There was a lot more troughiness across the eastern U.S. with lake snow well established (last year).”

The NOHRSC snow analyses for Dec. 16, 2011, shows that approximately 25 percent of the U.S. is covered by snow. This is only about half of the area of the country that had snow cover on Christmas Day last year, Dec. 25, 2010.

“This year, there has been one main storm track, from the Southwest and up into the central Plains. So, storm tracks have been much farther north and west compared to last year.”

The one and only area of the country that has more snow cover this year compared to last is the southern Rockies. Snow all the way down into northern Arizona and northern New Mexico is the result of frequent storms passing over the Southwest this year.

Meanwhile, there are some cities without snow on the ground currently that still have a shot at a white Christmas.

For instance, Minneapolis and Milwaukee do not currently have a snow depth, and a white Christmas is not totally out of the question yet with rounds of snow and cold possible leading up to Christmas.

Outlook for a white Christmas this year.

“There will be a subtle change next week with a farther south and east storm track,” said Rayno. “Any area that does not have snow now that still has a shot is the Midwest. This can include portions of Michigan and even Indiana and Illinois.” Lasting cold behind snow will be the wild card.