As we finish up this winter and head into spring and summer, we have had everything from record warmth to frigid temperatures and intense snowstorms. Now we head into the summer in just over a month, and it's already the middle of May. So yes, we already have early thoughts on next winter. Now keep in mind, these are very preliminary thoughts and could easily be turned around completely, but this is what we think could possibly play out for the winter of 2013 - 2014. If you have heard of the ENSO, this stands for the El Nino - Southern Oscillation. To summarize this factor, waters of the western side of the South American coast fluctuate from warm to cold, if you don't know the location I am exactly talking about, here is a map showing the area.
Now that you know where this region is, lets go a little more in depth, the seas surface water temperatures dictate greatly whether an El Nino or a La Nina will occur. If the water is warm in the region, it will be an El Nino. If the water is cold, it will be an La Nina. Now you might have thought, what if the water is warm, but now that warm compared to if the water is very warm. Well if the water is barely cold or warm, it's a weak El Nino / La Nina. Now if the water were to be pretty warm, but not very warm and not barely warm, then it is called a moderate El Nino / La Nina. Lastly, if the water is very warm or cold, then a strong El Nino / La Nina will happen. These facts are the basics to learning this impotent region.
For this winter, it looks either some sort of La Nina will form, or a weak to moderate El Nino. Now how I think one of these events could happen are based on the current actions of the sea surface temperatures in this region and the model guidance for the future on this area. Now lets start with the current conditions in this region. In March through the middle of April, warm waters took over the area and formed a weak - moderate El Nino. But this didn't last long because now the warm waters are beginning to vanish from the area. Especially right around the coastal regions, the cold waters of a La Nina are starting to take over. Here is a graphic from the CPC showing the past water of the region.
Now when I look at this map, the one thing that really stands out to me is how the oranges representing the warm waters are really receding from the area close to the coast and now only the light yellow and white colors remain. After that, another thing that stands out is the warm waters off central America, this does not greatly impact the El Nino / La Nina pattern very much, but is sometimes a site with a growing La Nina. So if you were to only base your forecast on the graphic, you would most likely predict a La Nina. But this is not the only graphic that shows current information. Another is this table that represents the El Nino / La Nina movement in the past leading up to the present.
This is pretty much just showing the same information, just on a graph. The La Nina also easily seen emerging on this survey called the Anomalies. Now the last graphic I wanted to show you about current information relevant to the emerging La Nina is the very recent, weekly movement of the seas surface water temperatures. This map your about to see really shows you the cold water that is taking over the region, and could stay and build, but it also could eventually leave in time for the winter, keep in mind that it's only May, and we still have a few months until we will have a better idea for what will happen with the ENSO, so here is the graphic and then we will take about the future of the region, and I will show you a model for the El Nino / La Nina forecast.
For this outlook information, things could get a little advanced for the average person, so just hang in there. The models show a weak El Nino occurring for the first part of this winter, possibly becoming moderate in the second half of next winter. Now I don't want to get into exacts because we are so far out, but that is what the models are indicating at this point in time. Now the more known models like the ECMWF and the CMC both show a weak to moderate El Nino. But the confidence on the outlook is not great at all and this forecast has a pretty good chance of being off. If you want to see exactly where I am getting this information from, here is the graph showing the model spreadsheet. The second graphic down shows you really how much uncertainty is in this very preliminary outlook.
Another thing you can see is that the neutral winter that we just exited from will most likely not be with us next winter, and that is that thing I am most confident on. Now I know you are wondering this, what happens with an El Nino / La Nina in play, what are the effects on the US? Well because we are possibly looking at a weak to moderate El Nino, here are the effects of a weak to moderate El Nino. There is normally a high just south of Alaska that forces the jet stream north over that high and then the jet stream skips the western US and dives down into the eastern United states. Causing mild temperatures in the northwest and north central US and colder temperatures on the east coast.
After that, there is normally a region in the southwest, in California and western Arizona is wetter then normal and the southeast and east coast is also normally west. Most often, the southeast has lots of rain and the northeast is snowy because of the above average moisture on the east coast and the cold air. But if we were to have a strong El Nino, which is not likely, but there would be almost the opposite, but that is not likely to occur. Now here is a map showing the impacts on the US when there is a weak to moderate El Nino.
These thoughts are my preliminary thoughts but there is still much more to be determined like temperatures and precipitation. Once again, take this outlook with half a grain of salt because anything that I said could change, so don't plan on everything that I said playing out. I should have my next update on the winter outlook sometime in late June, which will be my preliminary 2013 - 2014 Winter Outlook, but the things you have just read are my early thoughts for the 2013 - 2014 winter season. Come back in late June for my preliminary outlook. But as always tune into Northeast Weather Action for the latest weather forecasts and outlooks. Thanks for reading!