Snow cover in the Northern Hemisphere is a at record high for the past 56 yrs. And Winter is still nearly a month away. Did somebody lower the CO2 level in the atmosphere?
Data from Severe Weather Europe – Snow extent in the Northern Hemisphere at the end of November represents an important parameter for the early winter forecast. This year snow extent is running much higher than average and according to existing global estimates, it is now beyond the highest ever observed so far. Winter forecast, especially in its early phase and in Europe, might be strongly influenced by such a large snow extent, although many other factors need attention.
Northern Hemisphere snow extent is currently indeed very high, now at about 41 million square kilometers, according to the NOAA/Rutgers Global Snow Lab.
The Weekly Northern Hemisphere snow cover extent for the winter season 2022-2023 in purple is plotted together with the mean (grey dashed line), maximum (blue), and minimum (orange) snow cover extent for each week. Mean weekly snow cover extent and extremes were calculated using the 56-year period from October 1966 to July 2022.
Russia is completely covered in snow now. Snow is also seen overwhelming all of Canada, and Alaska, as well as a good portion of the Lower 48. This is an important parameter for the early winter forecast.
You could probably forecast a colder-than-normal winter based on Autumnal Northern Hemisphere snow cover extent alone. It’s the largest snow extent in decades. Having so much snow on the ground means any arctic outbreak is going to be a little bit colder.