White Christmas chances melting away

Wondering about our chances of having snow for a second consecutive Christmas?

Well, the Fat Lady might not be singing yet, but it doesn't look like "White Christmas" will be in her repertoire for 2011.

A winter storm provided the Charlotte region with a holiday thrill last year, as several inches of snow fell over much of the area -- although much of it fell early on Dec. 26 in Charlotte.

But the pattern that provided us with a brutally cold December and the white Christmas in 2010 is nowhere to be found this time around. That's the reason for our regular stretches of 60-degree-plus temperatures this December.

In fact, many of Carolinas residents who travel up North for the holidays and expect to see snow might view bare ground instead this year.

"Most of the Mid-Atlantic, southern New England, and the Southeast are likely out of the running for a white Christmas," says Alex Sosnowski, a meteorologist with Pennsylvania-based Accu-Weather. "There is too much mild air for snow in those areas."

And if the pattern doesn't change, we might be looking at a very mild winter.

La Nina conditions are present for the second straight year. La Nina (colder-than-average water temperatures in the eastern Pacific) brings mild and dry weather to the South. Cold air and storm systems typically hit the Northwest, upper Midwest, and upper Great Lakes.

Last year, La Nina was overwhelmed by another condition -- the Greenland Block. That is a strong high pressure system over Greenland, and it tends to steer arctic air into the eastern United States and also into Europe. It meant the Arctic Oscillation (AO) was negative, as the upper atmospheric pattern looked like the Thunder Road roller-coaster at Carowinds. The eastern United States was at the bottom of the tracks, and the arctic air tumbled down the tracks from Eskimo country.

"This year, that block is not present," says Scott Krentz, a meteorologist at the National Weather Service office in Greer, S.C. "So La Nina is a major governing factor in our weather."

In addition, a strong subtropical high pressure system is establishing itself over the South. That is keeping cold air far to our north.

How long will this condition last? Sosnowski, Krentz and other meteorologists don't know. Computer models only give us a two-week window into the future, but weather patterns don't tend to change in a hurry.

So it might turn cold in January, but odds of an icy and snowy start to 2012 are lower than they seemed a few weeks ago.

Here are predictions on white Christmas chances for some major cities, courtesy of Accu-Weather:

Probable: Denver, Milwaukee, Minneapolis-St. Paul, near Pittsburgh (especially east), eastern West Virginia, Buffalo, Syracuse, and inland New England.

Doubtful: Chicago, Cleveland, St. Louis, Cincinnati, New York City, Washington, Baltimore, Philadelphia and Boston. (Note: Detroit is between the "Probable" and "Doubtful" categories)

No: Charlotte and everywhere else south of the Mason-Dixon line.