Thursday Evening: WINTER OUTLOOK

Alright folks...here is my official winter outlook and what I think may happen this winter. Please keep in mind that what follows is just my best estimate, and is, at least to me, going to be the most difficult winter to forecast in the last few years. There are SO many variables that could change the outcome, and some people think that forecasting for an entire season is crazy, and for good reason. Just one simple little difference in the Jet Stream configuration could drastically change whether we see a cold winter or a warm winter. Now many of you may have heard rumors that La Nina is developing in the equatorial Pacific Ocean waters. This occurs when the deep, cool waters are pulled to the surface, resulting in below average waters that spread across the Ocean, and depending on how strong it becomes, can cover either a little or most of the equatorial waters. Believe it or not, what may seem like just a simple little temperature change can, in fact, have a DRASTIC affect on not just the type of pattern we have, but the globe as a whole. La Nina is the opposite of El Nino, which is the warming of the equatorial Pacific waters. Now, right now, La Nina is barely in a weak state, and this is very important in determing whether or not this will affect our winter this year. Here is a picture of the latest temperature departures in the La Nina area. Now, as you can see, the area just off the coast of South America is where the most noticeable change in temperatures are occuring. However, notice that they don't extend very far West yet. Now, while they have been shifting Westward, it's not doing so at a alarming rate. In a strong La Nina regime, the entire region West of South America would be entirely below average. But we haven't seen many strong La Ninas' dating back to 1980. I believe there have only been 5, and I highly doubt that we will even get to a moderate stage. With that being said, the latest models are actually forecasting the temperatures to even out, and in most cases, even rise some. What does this mean? It would put a stop to the dropping temperatures, which would mean that a weak La Nina would occur at best. Most likely, this wouldn't have a huge affect on our pattern. But if it did, what would it bring? Well, in strong La Ninas, we would have a dry, and rather warm winter. But in weak and moderate La Ninas, we actually normally have at least one decent snowfall during the winter, and normally during the month of December. Unfortunately, Spring usually arrived early. However, am I banking on us having a weak La Nina type pattern? Right now, I'm very skeptical of leaning one way or the other. I am very concerned leaning towards a La Nina pattern, because last winter El Nino developed, only to disappear, having no affect on us last winter. And I am concerned that perhaps this La Nina is going to do the same thing: just disappear, and with the models hinting at warming temperatures, I'm beginning to wonder if that will happen. However, I have to keep in mind that La Nina conditions could affect our weather as well this winter. So, what about this fall. Well, obviously, we are already off to a warm Autumn season. I think the fall foliage peak will occur a few weeks later this season. I think that once we head into late October and especially early November, we will see a cooler weather pattern develop. But in the meantime, the models look very bleak for any type of cold weather the next few weeks. I believe the rest of this Autumn season will very dry overall as well. Now, what about November? I think overall we will see cooler weather, and hopefully we will have a cool Thanksgiving. Already we are seeing very different conditions compared to last winter. Now, from December to March, things become a little more questionable. It's very uncertain what will occur, but I believe that especially the Midwest will have a very cold and snowy winter, with periodic cold spells here into the Southeast. Depending on whether or not the Southern Branch of the Jet Stream brings storms into the Gulf, we WILL see some snow this year. My hunch is that we will see 1 decent snowstorm, and when I say decent, I mean at least 3" of snow. Obviously the mountains will see more. What will be very important as well in this winter season is the PNA (Pacific/North American Oscillation), NAO (North Atlantic Oscillation), and AO (Atlantic Oscillation.) Usually what brings cooler air into the East is the NAO when it is in a negative phase. And here is what I mean. This is a chart of the NAO index. The PNA and AO ones look exactly the same. The Black line is what has occured, and the red lines are the models projections of what they think will occur (though they are highly unpredictable.) Anyway, whenever the black is below the 0 line in the negative numbers, that means the NAO is in a negative phase, which would typically point to blocking in Canada which allows cold air to filter down into the Eastern US. The PNA works a little differently, and normally when it's positive, the West is colder and the East in warmer. This is how a lot of forecasters predict colder air coming. While not always effective, it's a great indicator of where the pattern is going. I'm using this a lot in my predictions, and notice how during most of this summer, it was negative. This doesn't play a role in our weather much during the summer season, but it shows a pattern. It makes me think that we may see some ups and downs in the NAO index this winter, which would mean cold spells and warmer spells. But if that NAO takes a nosedive, and we can get a storm in the Gulf, then we could see some good snows this year. I'm sorry if this all seems a little boring and off topic, but I figured I would kinda explain some things and show you as I wrote out my winter outlook. And this is just one little thing that forecasting look out when making projections and forecasts. Hopefully your beginning to see how difficult it can be to make forecasts, and why meteorologists are often times wrong. :-)
So, here is a "outline" of my thoughts:
1.) The Autumn season will remain warmer than normal, with cooling weather during November. I don't see much hope for drought busting rains.

2.) I expect one decent snowstorm this winter, which will probably occur during the month of December or January. The decent snowstorm will drop at least 3" on the valley floor, with much more in the mountains. More light snows will occur this winter.

3.) The NAO will take some wild swings, meaning we will see some drastic temperature affects. And assuming that the PNA isn't positive most of the winter, we will see some true cold air. My concern is that the Pacific Northwest will get locked into a stormy pattern resulting in mostly mild temperatures in the East. Then again, this would occur mostly if the La Nina pattern does occur, and again, I'm not convinced that it will.

4.) Hopefully we will start seeing more rainfall once we see a major pattern shift. We have a serious drought that just doesn't want to go away...

I want to point out something very important. What would change the outcome of the this winter the most is actually what will occur out West. If the Pacific Northwest gets locked into a stormy pattern, then this could cause us to have warm weather. Why? Depending on how the storms track into the PNW, they would actually help to draw UP warm air from the Gulf of Mexico as they track to our North. I am hoping very much that this doesn't happen, and it occurs more in a strong La Nina which I don't expect will occur. But then again, it doesn't take El Nino or La Nina for that to happen. If you remember a few years ago, we had a similar pattern which lead to a remarkably warm January. Anyway, just pointed that out to let you know how it could be a warmer winter overall...
That's it for now...PLEASE post a comment if you have any questions, whether it be me needing to clarify something, or whether you have a question about something I didn't mention. Have a great evening everyone...sorry I don't have time to post more. This is just my intial outlook, and again, could be wrong depending on what pattern(s) occur over the next month or so. Normally you can get a good idea of what the weather will bring during the winter when the cool air finally begins marching in just based on the NAO and such...stuff I don't have time to go over right now.

Also, I'm sorry if I seemed a little "scared" of saying whether the weather will be this or that. This is the first time I've actually posted an entire winter weather projection, and I'm still uncertain of several factors that weren't mentioned above. So I'll leave you with this: this winter is very uncertain. It could either be very cold or mild in my interpretation. I don't expect records warmth, and even if it does average warmer than average, it won't be drastically warmer. So I'm sticking to that much. So we'll see how it turns out! And sorry for any typos in the outlook...I didn't feel like reading over it over and over again to find them. :-)