First of all, thank you for taking the time to read up on my thoughts for the upcoming winter.
I really do enjoy putting these together and attempting to do one of the most difficult things imaginable...predict WAY into the future. Just ask the people who were running polls to see who would win the presidency, and ask them how difficult it is to predict the future! ;)
So much goes into my forecast and I rely on many different resources to come up with my final conclusion. I will go through some of those different factors below. But first I want to show you what the NOAA winter forecast is for this year.
Updated about a month ago, the NOAA winter forecast shows both a temperature and precipitation forecast for the U.S.
In terms of temperatures, they are forecasting a slightly higher chance for warmer temperatures across the southern half of the U.S. with part of the Ozarks in the warmer sector, but the northern half with "equal chances". In other words, it could go either way. (Just a note, the star on the maps below is where Springfield is located).
When we look at precipitation for the winter, all of the Ozarks sits in the "equal chances" on the NOAA map, or, again as I would put it, it could go either way! It shows drier than normal conditions to our south, but, up in the northwest and the Great Lakes region, there is a better chance for above normal precipitation.
One of the first things most forecasters will look at when determining a winter forecast is whether or not we are in an El Niño or La Niña pattern.
The best way to see that is by looking at sea surface temperatures in the Pacific Ocean near the Equator.
As you can see below the colors represent what are known as anomalies, or basically how many degrees warmer or colder temperatures are than the average.
The blue colors showing up near the Equator show the cooler than normal ocean waters and point to a -1° anomaly, which means a La Niña pattern. You then look at how weak or strong the La Niña is based on how many degrees cooler or warmer that ocean water is. With just a -1° anomaly this would be considered a "weak La Niña". This will come in handy below when we look at comparable years so keep that term in mind.
Let's look at the forecast for the La Niña conditions to continue through the winter. On the graph below, you are looking at the fourth column, DJF. That's the forecast for December, January and February. It shows
the La Niña conditions having a 55% chance of continuing through the winter.
The graphic below shows just a basic representation for what a typical La Niña pattern brings over the course of a season across the U.S. Of course we sit right in the middle of the pattern where it could go either way for the Ozarks. Cold air just to our northeast and warmer air just to our southwest.
Now, let's look back over the years to see which ones had strong or weak El Niño and La Niña winters. You will see on the right side if it was weak, moderate or strong El Niño or La Niña.
If you can't see that one very well, here's another graph breaking it down into columns. Remember, we are looking at a "weak" La Niña year. The graphic below breaks down the years since 1950 and whether or not they were, weak, moderate or strong.
I look at all these "weak La Niña" years, and try to match one of those winters with the current global pattern. The year I like the most is the 1964-1965 winter. Many of you may not have even been alive during that winter. If you were you might not remember it because it was a rather typical winter. Here's what that winter had in terms of temperature, rainfall, and snowfall.
Let's look at some of the other years with a "weak La Niña" and what the snowfall amounts were. Keep in mind, 17" is the normal snowfall amount for Springfield in a season. As you can see below, four out of the five that we looked at had below average snowfall. Only one had an above average one. There of the five were just a few inches below normal.
One of the other key factors in forecasting for the winter is what kind of phase we are in when it comes to the arctic oscillation. The AO, is either positive or negative. The positive phase keeps cold arctic air locked up to our north and often won't spill down to the U.S. The opposite occurs when the AO is negative. The jet stream is positioned in a way that allows cold arctic air to plunge to the south and into the U.S.
We have been in a positive phase for much of the year, which contributed to the unusually warm fall we have had, but forecasts show the AO will go negative as we head into winter. That would allow for that cold air to spill in, especially as we head into the month of December.
Here is another one interesting to look at, and it makes sense if you think about it. Snowpack in Siberia during the fall months may impact how much cold air can get pushed down into the U.S.
This first graphic shows the percentage of snowpack from last year. Notice that the colors are more orange, yellow, and green which corresponds to 25%-70% snow-pack.
Now look at it for this year, WAY more snowpack. As a matter of fact much of the area is at 100% snowpack as seen by the dark blue in that area. This means much colder air is locked up up there and can traverse across the large landmass and into Canada and eventually here into the U.S. I think we will be on the edge of some of these very cold arctic plunges during the upcoming winter.
Also solar activity has been said to play a role in winter patterns. When solar activity is high, there are fewer cold snaps but when solar activity is low there are more.
So let's see where we are this year. If you look at this graphic below, you will see a downward trend. It is forecast we hit our lowest point or "maunder minimum" somewhere around 2020. So, since the solar activity is low, there are more cold snaps, and that would lead us again to believe more of them during the next five or so years.
After looking through all of that I am ready to give my 2016-2017 winter forecast!
While last year we had a VERY warm winter, I think the upcoming one will be a little more typical with varying warm spells coupled with cold blasts of air. This will help balance the overall average and make it near normal.
I think the month of December could be quite cold as some of that arctic air plunges to the south. I think January should be fairly typical, but then February brings back some of the warmer temperatures to wrap up winter.
On average I am going with -1° to +1° for temperatures. To put that into comparison, last winter we were nearly 5° above average.
When looking at rainfall amounts the average is 11.5" and last year we had nearly that much in JUST the month of December. I think we will not have wild rain amounts like that this time around.
Instead, as has been the case for much of this year, we will see below average rainfall for the winter. The Gulf of Mexico has essentially been shut down for months and the current pattern doesn't lend itself to big rainfall events.
I'm going with 7"-10" of rain for the season with fewer storm systems here in the Ozarks through this winter.
Okay, here is the one everyone wants to know about! SNOW!
First, our average snow is 17", but you may recall last year we only had 3" for the entire season!
Snow lovers may be disappointed again this year, but I am a little more optimistic that we will have a few snowfall events that will bring us measurable snow a handful of times this season. Many of the previous winters with this current pattern have brought snowfall amounts just a little below average. I'm going to stick with that as my forecast for this year as well. Below average snow!
With that being said, I'm still thinking a 10"-15" snowfall range is not out of the question. I think this will come in three or four smaller systems. But, by the time the season is over, we should be able to get those totals up to more than what we had last year.
The only other thing I would like to mention is the severe weather threat that sometimes pops up during the winter months. We have seen some La Niña winters in the past have rounds of severe weather, but we may be struggling to get that with less moisture and the Gulf of Mexico "shut down" (as I explained earlier). So for that, I"m saying our chance for winter tornadoes are lower. We will have to watch February though as we step closer to spring.
Below is a recap of my thoughts for the winter.
Well that pretty much does it! Another one in the books! Now we can just sit back and see what happens. After all, it really is out of our hands at this point. Let's just hope my forecast is better than those election polls were this year.
Have a great winter and don't forget to enter into our first snowfall contest! Your chance to win a generator if you guess the day Springfield gets the first 1" of snow. (make sure you read the rules!)