Winter Weather Outlook

It is never easy to tell people ahead of a season how it will turn out. The best we can do is give you an educated guess. We do know one thing about the upcoming winter, BUT there is also a Wild Card in there, too.
 
We will be in a La Nina pattern just like last year. This is when the waters of the Pacific Ocean are cooler than normal; this effects weather Patterns around the world. This means the drought will likely continue in Texas. In a normal La Nina pattern, our winters tend to have above average precipitation and above average temperatures. However, occasional drastic temperature swings take place. Normally that would be what I would say about this year: Wet and Mild with Occasional Shots of Cold Air and always a chance of a few snows.
 
However, last winter was much colder than a normal La Nina Winter, and we are not exactly sure why. It is something called the Arctic Oscillation which simply means the polar air drops way to the South. An episode like this can last a few weeks as it did last year. Will it happen again this year? We are not exactly sure. It is possible that we may see another period of very cold weather for several weeks this upcoming winter. If Gulf Moisture arrives at the right place and time when cold air is here, we could see several snows again just like we did last year. The Mountains saw a lot more snow than the Valley last year, although we did have the first really “White Christmas” in 35 years.
 
So on the whole, I will call for a mild winter, but a period of very cold weather for several weeks is possible. I also think we will see above normal precipitation, and as always in any winter, if all the right ingredients set up, we may see average to slightly above average snow this season just like last year.
 
I HATE to even bring this up, but the La Nina also was responsible for the severe weather we saw last Spring. If this pattern continues, it could be another rough Spring for the United States. La Nina's also produce above average hurricane seasons, although they don't have any effect whether they make landfall or not.
 
So this is my official "Guess Ta Mate" for the Winter of 2011-2012. I always say the best and most accurate way to discuss the winter is let’s get together and talk about it next March....lol
Oh Well....Time will Tell.

-Chief Meteorologist Bob Becker

My personal take on the winter forecast...

Looking at current trends, it appears that the early part of winter may be slightly warmer than normal with a lesser chance of snow. The La Niña pattern means a lesser chance of precipitation in the Southeast United States and a continued drought in Texas.

However, La Niña is not the only controller of our weather here in East Tennessee. One of the strong factors in the cooler, stormier winter last year was the negative NAO (North Atlantic Oscillation) index. During the winter of 2010-2011, the NAO was often negative (between -0.5 and -1.5) which brings more troughing in the jet stream and thus "spills" more cold air into the Eastern United States. This also can allow storms to strengthen coming up the East Coast and threaten the eastern part of the country. For this reason, I believe the NAO is the chief factor that will determine if we have a cooler, warmer, wetter, or drier winter since the La Niña pattern gives us equal chances of warm/cold and wet/dry weather here in East Tennessee.

The current and forecast NAO is very uncertain, but the NAO has been trending positive over the past month or two after a long period of time with negative conditions. If this positive trend continues, it would mean warmer conditions with lower chances of snowfall during the November and early December time period. We will continue to monitor conditions throughout the winter.

As a sidenote, remember that seasonal outlooks are based on averages and trends. Winter storms can still occur with dangerous conditions, and these storms are often difficult for anyone to predict more than 7-10 days out. We here at the East Tennessee Storm Team will always monitor these situations and keep you informed!

-Meteorologist Jeremy Buckles