Things that used to happen a lot, like consistent winter snow cover, are happening less reliably. (dotearth.blogs.nytimes.com)
See: Ministry Of Truth Announces «record retreat of snow cover in the Northern Hemisphere» — But it was the «second largest winter snow cover on record» (climatedepot.com)
A thick early winter snow cover in the region refrigerates the air directly above, strengthening the temperature contrast with the Arctic Ocean and reinforcing the entire pattern, Haustein explains. (psmag.com)