Meteorologists have uncovered dozens of indices that can be forecasted on a short term basis, with several being predicted on a long range time frame. However, there are models that forecast the *long* range, and they are not to be discounted. Let's take a look.
UKMET Long Range Model
The two images above are the probability of above or below normal precipitation (top image), and above or below normal temperature anomalies (bottom image), valid for December-February 2012-2013. The UKMET is known to be pretty close with the ECMWF, as they are both from Europe, but verification is another matter.
Either way, each model has its say, so let's take a dive into the UKMET. The model is saying that the Plains states and some residents in the Rockies may get in on slightly above normal temperatures come winter. This anomaly is reflected into the Ohio Valley and much of the Gulf Coast. The upper Great Lakes and areas of the Northern Plains end up below normal in the temperature department. For precipitation, the West Coast and Ohio Valley find themselves in a wet situation, with spots of the South also getting in on the fun. However, dry weather is forecasted for scattered regions along the eastern Rockies.
The Japanese, known for their infamous JMA model, have a long range model as well. This is based off the JMA model, but before you discount it, remember that each opinion is valid, much like Freedom of Speech.
The JMA prefers a chilly situation across much of the western 2/3rds of the nation in the bottom image, with warmer temperatures across the East Coast. Precipitation is below normal in the same western 2/3rds and above normal in the Eastern US. This looks like a fairly valid solution- the Equatorial Pacific is fairly neutral across the board, and below normal precipitation anomalies in the northeast Pacific indicate a ridge in place, which the JMA seems to be handling correctly as far as effects on the US.
These are just a few of the long range models people are looking at for this winter. There are many more that are out there, some of which you can find on our famous Weather Models page.