Winter 2012/2013 early look

East Tennessee Winter Outlook 2012-2013

By Chief Meteorologist Bob Becker and Meteorologist Jeremy Buckles:

Scientifically, there are three large-scale patterns that can affect our weather here in East Tennessee: the AO (Arctic Oscillation), NAO (North Atlantic Oscillation), and ENSO (El Niño/La Niña/or Neutral). The AO is positive and trending positive which normally means not as much cold air intrusions into the mid-latitudes. The NAO has been negative which would allow blocking off of the Eastern U.S. and allow cold air to push into the Eastern U.S. and stay for a longer period of time. However, it is trending positive and looks somewhat similar to the pattern a year ago. That shows us that the NAO is trying to trend back positive once again which would lead to less cold air staying for a long period of time over the Eastern United States. The ENSO is clearly trending to an El Niño pattern and most climate forecasters agree on this. For this reason, we forecast a mild to moderate El Niño during the winter months. This tells us two things. First, the pattern looks to be conducive to temperatures that are normal to above normal (this is not saying that we won’t have some cold snaps…it just looks to be normal to above normal temperatures for the average over the winter). It also looks like that when we do have cold snaps that they will be shorter. Second, with El Nino, I expect to see more precipitation over the Southeast U.S. and Southern U.S. in general. That means we should expect to see above normal precipitation. Now what everyone will want to know, putting the precipitation and temperature forecasts together, it appears that we will see normal to below normal snowfall over the valley while the higher elevations (such as the Smoky Mountains and Cumberland Plateau) could see normal to above normal snowfall. The terrain is always a big factor, but it could be a bigger factor this year. In many cases, the higher elevations may be cold enough for snow but lower elevations will not be. However, there is a higher chance of a significant snowfall this winter across East Tennessee compared to last year. With higher precipitation totals, and much of this coming out of the Gulf of Mexico, there will be a higher chance of a big snow if this can meet up with cold air over our area. Essentially, if the wet and winter-like pattern continues like we’ve seen through September, it will provide us with the chance of some big snows depending upon if we have enough cold air in place. So snow lovers, stay excited and stay tuned! There is a higher chance of a big snowfall compared to our winter last year!

As trends change, we will make adjustments and let you know!

Toot wrote:Accuweather winter snowcast

Stovepipe wrote:

Toot wrote:Accuweather winter snowcast

John1122 wrote:Very detailed and hopefully correct forecast.

http://torontowxcenter.blogspot.ca/?m=0

Stovepipe wrote:Wow, that was a very very interesting write-up. The best I've read so far about the upcoming winter. It's difficult to not get excited after reading that if you love snow and live in TN. Excellent find John and thanks for sharing!

Toot wrote:CPC made a huge shift in their three month outlook!

They went from warm in the east (Previous outlook)


To warm in the west (Current outlook)


Definately more of a Nino look. I havent read their discussion..but I wonder what data made them make such a drastic shift?

skillsweather wrote:Just wait if this winter becomes snowy they will change it the next day and claim they got the forecast correct. I seen it happen before (although not that extreme ofc lol). I would love to see them have us in like 60% above normal then by early January have them have us all in 60% below normal.

snowdog wrote:
I think the main reason they changed their forecast was due to the busted Nino. Also, would it kill them to throw some blue on the graphic? Surely we aren't going to torch 2 winters in a row.