Forecasting a Cold Winter

I'm not a great believer in long term weather forecasting, so I'm a little sceptical to this article forecasting a colder than usual winter. However, the case laid out in the article makes sense, and is interesting in light of the current obsession with our climate.

Contrary to what was forecasted by climate experts, such as Al Gore, back in the 1990s, and Greta Thunberg in the 2010s, the world isn't seeing any less snow during winters than we used to see, and this winter is already on track to break all records.

This might sound dramatic, but the records only date back 56 years when satellite observations of the climate first started. We are at the moment seeing snow cover a little in excess of the record held during these 56 years. It's not exactly proof of anything. However, it doesn't bode well for those who've been hoping for a mild winter, because early snow extent is a good indicator of how cold a winter is likely to be.

This is based on simple physics, and has been verified by experience, so the odds of us getting a mild winter are slim.

The primary reason for the correlation between early snow extent and cold weather is the albedo effect that comes with snow. Sunlight is reflected by snow and prevents air close to the ground from heating up.

The other effect is due to the energy required to perform phase transitions. Melting snow and ice prevents air close to the ground from heating up due to the energy required to transform frozen water into liquid water.

With all of Russia and Canada already covered with snow, cold air will be allowed to build up in these areas and produce arctic blasts that send temperatures lower.

However, all of this affects only the low-level air close to the ground. It ignores temperature variations in oceans and higher altitude air-masses. To read a lot into this would be like taking air temperature measurements only at ground level and deduce that the climate must be changing due to changes measured only about 1.5 metres above ground.

Greta Thunberg

Eco-anxiety - By Anders Hellberg - Own work, CC BY-SA 4.0, Link