Winter doesn’t officially begin for another month, but we’ve already seen some early winter weather. So far to date, Peoria already has over 5″ of snow. The average for the month of November is just over 1″.
To answer the question of what is our winter going to be like, I’ve used a combination of the latest forecast models and something called analog forecasting.
The central and eastern Pacific Ocean is a good place to start to determine our weather for the upcoming winter. This is where El Niños and La Niñas occur. This winter I’m expecting an El Niño to develop, which is a warming of the waters in the central and eastern Pacific Ocean. This can be seen by the warmer colors in the graphic below.
Since 1950 there have been 7 moderate El Niños. I had a chance to look back at those years to see what they brought for Peoria.
The strongest correlation was below average precipitation, although there was still a trend for below average snowfall and temperature during these years.
While this El Niño is a good place to start, it doesn’t paint the whole picture. Using the latest forecast models, I have an idea of what the atmosphere and oceans will be doing over the next few months. Going back in time, I have found similar patterns in 7 years. These are our analog years for the winter. While the list is similar to the El Niño years, it isn’t an exact match.
The idea behind analog forecasting is going back in time to see what happened when the pattern was similar and using those results as a precursor for our future weather. While there was still a trend for below average temperatures and precipitation, there was not a clear trend for snowfall.
Here is a more detailed look. While it’s a slim majority, more than half of the years had above average snowfall.
These 7 winters on average produced very cold conditions for the eastern United States and in particular the Southeast and Mid-Atlantic states. This is where the highest deviation from average was. This map shows the average Dec-Feb temperatures for these 7 years, but note the map is in degrees Celcius.
The weather pattern generally featured a ridge in the west and a trough in the east. This combination is what allowed for such cold conditions for the eastern US as cold air was brought south from Canada.
Overall, I am expecting a similar weather pattern to develop, which will lead to warm conditions on the west coast and a cold eastern United States. The coldest weather relative to average will be from the southeast into the Ohio River Valley and Mid-Atlantic.
It is worth noting that a couple of the analog winters are in the top 10 coldest and snowiest. 1977-78 made both lists.
My outlook doesn’t call for conditions this extreme, but it will still be a cold and snowy winter relative to average. However, it is worth noting that if this outlook is incorrect, I think it will be colder and snowier than what I am predicting.
This winter’s snowfall should be fairly comparable to what we saw last winter. Remember, snowfall totals count from first flake to last, so we are looking at snowfall totals from now until late winter/early spring. I think it will be a much colder winter than last year with the core of the cold coming in early 2019.
-Chief Meteorologist Brian Walder