As 2012 comes to a close we will be going into a new year but at the same time a brand new season and that is Winter. Winters in Southeast Tennessee are typically mild compared to other parts of the country. A typical Winter day will see a high about 50 and night time temperatures drop to around 28 degrees. Snowfall is scare but it can fall usually Southeast Tennessee averages about 5 inches of snowfall the mountains average much more. Some winters see no snow while some see a few. For example Winter of 2010 saw 14 inches of snowfall due to an active jet pattern and cold air. Winters can also bring severe storms and some winters have it all snow, severe thunderstorms. So what will winter of 2013 be like?
To be honest this type of winter is hard to predict because while there is an El-Nino, which usually brings colder air and increases winter precipitation it is not a strong El-Nino. In 2009 we had a strong El-Nino which carried other into early 2010 before changing into a La Nina pattern. The 2009/2010 winter we saw 14 inches of snowfall. But as I stated this year’s El-Nino is not strong. Weak El-Nino’s tend to cause colder than average Winters for our area but how much do they influence snowfall is up in the air. Some weak El-Nino’s have brought snowfall and ice storms others have just brought colder conditions. Here are several scenarios that could happen.
Scenario #1 is the El-Nino strengthens in that case we would have greater chance of snowfall and ice storms and much cooler than average temperatures. Moderate to strong El-Nino’s cool the Gulf of Mexico and Atlantic Ocean temperatures while the Tropical Pacific water temperatures warm up. The Western United States tends to be warmer but the East is much colder. If this scenario happened then Southeast Tennessee could see a few winter storms.
Scenario #2 the El-Nino stays the same intensity, this is the most tricky most likely the temperatures would be below average. Their would probably be a few winter storms but not significant ones, what I mean by significant is a bad ice storm or a snowstorm over 6 inches. On the other hand, this one is tricky because weak EL-Ninos have produced some significant winter storms. Most of the time the jet stream patter is low enough to bring snow but the cold arctic air stays further north. However sometimes the arctic air is able to dive south which would enhance snowfall
Scenario#3 The El-Nino dissipates and we go into a Neutral pattern. If this scenario happens we would probably have an average winter with near normal precipitation, near normal snowfall and temperatures would probably be average.
Scenario#4 El-Nion dissipates and La Nina returns, this one probably will not happen. If it where to happen depending on the strength of the La-Nina our temperatures would be above average but snowfall would be scarce but we would probably have a better chance of seeing severe thunderstorms instead of ice storms. Note that severe thunderstorms can be possible in all scenarios if the conditions are right.
So how will 2013’s winter will be like? In my opinion i see Scenario 2 and #3 happening, #1 could happen but usually stronger El Nino’s have already been in full swing come Late November so while it could happen and it cannot be ruled out, the pacific water temperatures have not warmed up which would indicate it getting stronger
I think we will see temps slightly below normal, I do think we will have a few chances of snow, but unless the El-Nino really strengthens we probably will not see several significant snowfalls. Rainfall amounts look to be average to slightly below average