What’s the upcoming winter look like? Are there any early indications?
Seasonal forecasts for the December through February meteorological/climatological winter period will be the subject of more and more posts from reputable global meteorological centers in the weeks and months ahead as we make our way toward and into the coming cold season.
Here are some early entries from such centers, including early projections from the National Weather Service’s Climate Prediction Center, Environment Canada, the European Centre and blends of forecasts from multiple models out of a series of national meteorological centers. What follows are but a sampling of seasonal forecasts produced here in the United States and around the world.
The La Nina out in the equatorial Pacific (the cooling of ocean waters along the equator West to the Date Line and an accompanying increase in the easterly winds which blow in that region) may play a role in the upcoming winter here in the Chicago and the Midwest. It’s been established that changes in ocean temps and winds there can have global weather impacts.
There’s been a bias toward above normal precipitation in the winter season here in Chicago and the southern Midwest in many La Nina periods of the past. There is also a tendency toward temp volatility.
But each La Nina comes with its own character so it will be interesting to follow developments as they evolve in coming months.
Seasonal forecasts aren’t carved in stone. There are so many variables involved in the creation of winter weather patterns.
References to things like Siberian snow coverage, linked ocean/atmosphere cycles bearing names such as La Nina, El Nino, the Arctic Oscillation, the North Atlantic Oscillation, etc. are discussed. So are projections of rapid stratospheric warming over the poles.
Increasingly, seasonal forecast are generated from “ensembles” or collections of computer forecast models which are blended or averaged.
Projections over weather trends over such extended periods of time are unable to pinpoint individual storms, cold waves or warm spells.
If you hear estimates of how many snows will fall and in what ranges of accumulation, be wary! The ability to produce such predictions is beyond the art of the science in this day and age–and may always be. Instead–and there’s been some skill identified in these forecasts—the hope in seasonal forecasting is to look toward general trends in temp and precipitation which may be on the horizon.
Having said all of this, here are a few early projections of general conditions for Winter 2020-2021.
It should be noted that an above-normal 3-month December through February temp prediction does not mean there will be no arctic outbreaks or that every day will be mild. Not by a long shot. Nor does an above-normal precip forecast indicate that we’ll necessarily see all of it fall as snow. But it’s interesting to keep a running tally on current thinking–and that’s the idea in looking as some of these early projections.