The 2013-14 winter was a season that I will never be able to forget simply because of the kind of cold Arctic outbreaks that occurred throughout that year. What’s even more remarkable is that the 2013-14 winter became known as that winter that simply would not end, and even this summer, we have seen times when the mid and upper level pattern strongly resembled what would be typical of a winter pattern. We had pretty severe Arctic outbreaks in both 2009-10 and 2010-11 winters but for entirely different reasons than last winter. The main driver of last winter was the warm pool of above average waters over the northeastern Pacific, and this warm pool is still there! It is to blame for a lot of the volatility that we have seen this year in our temperatures across the United States.
You hear a lot about the North Atlantic Oscillation (NAO) and Arctic Oscillation (AO) particularly during the winter months as those indices are very important to monitor each winter and can be the difference between a cold winter in the central and eastern United States and a very warm winter. Last year, it didn’t matter whether we had a positive or negative NAO/AO, and for those of you that followed my forecasts last winter, you may remember me telling you to ignore all the forecasts being put out that were predicting a big warmup simply because the AO/NAO wasn’t negative. It’s rare that you would hear me say something like that, but the reason that it didn’t matter was because of the warm pool in the northeastern Pacific. It led to a more volatile pattern, and even the regions further south and southeast that didn’t necessarily lock into a cold pattern experienced below average temperatures for a good portion of the winter because of the frequent Arctic blasts.
The 2014-15 winter could also be strongly influenced by the warm pool in the northeast Pacific if it persists going into the winter months, and based on some of the things that I have been looking at, chances are good that it will. This would likely lead to another brutally cold winter in the central and eastern United States while the western U.S. would have above average temperatures, particularly in the Pacific Northwest. The good news is that I think central and southern California will receive above average precipitation, and that is due to a developing weak El Nino that will not necessarily be the main driver of this winter but will have some influence. This also means more precipitation across the southern states including the Southwest through the Southern Plains to parts of the Southeast. The regions where the cold air will be in place will have an increased chance at seeing more wintry weather this season, even in locations that typically don’t get any snow/ice.
When there is a warm pool of above average sea surface temperatures over the northeast Pacific/Gulf of Alaska, you get ridging to develop up over Alaska and the western U.S. and troughing over the central and eastern United States. This can persist throughout the entire winter (just like last winter) if this warm pool remains in this same place throughout the season. This is what is considered a negative EPO (eastern Pacific oscillation) pattern and typically brings cold air over a large portion of the United States. Due to some other factors that I will explain in a future article, I have reason to believe that the cold air could be more focused in the eastern third of the nation this winter.
There are still a lot of unknowns about this winter, and I am going to monitor everything closely through September and October before I put out a final 2014-15 winter forecast in late October or early November. There have been a lot of bogus forecasts being put out on this upcoming winter, and you just have to ignore them. I strongly believe that this could be another brutally cold winter, and if anything changes my mind, you’ll be the first to know. Remember, there are sites that call for brutally cold winters EVERY SINGLE YEAR just to get high views, but as most of you know, if I think something is going to happen, I tell you WHY.
Here are two links for you to check out: this one here will take you to my region-by-region breakdown on this upcoming winter, and this one here will take you to my detailed winter forecast that gets more into the meteorology behind the forecast. Also, be sure to like Firsthand Weather on Facebook, where I will be putting out updates on this upcoming winter and other weather events.
Matthew Holliday (Curriculum Vitae - Resume) is a graduate of the University of Oklahoma, where he completed a B.S. in Meteorology and a B.S. in Geographic Information Science. He completed his master's degree in meteorology and climatology at Mississippi State University and is currently pursing a Ph.D. in Earth and Atmospheric Sciences.