Eurasia Snow Cover 10th Least Snowy in December 2022; Last Week of December 4th Least Snowy

Fig. 1: Northern hemisphere snow cover rankings for December 2022 vs. past 3 years according to Rutgers University Snow Laboratory.

Discussion: December 2022 ranked 21^st least snowy in the 57-year climatology for the northern hemisphere. The observation is heavily biased by the 10^th least snowy December on record for Eurasia. In Europe, the last week of December ranked 4^th least snowy in the 57-year climatology trailing 1980, 2017 and 1974. The northern hemisphere thermal climate in December was wild featuring both a historical arctic outbreak in the U.S. during the week prior to Christmas Day and a warm to record warm transition through December across Europe. The last week of December was also quite mild across Russia. By the last few days of December, North America shifted into a very warm pattern.  The December 2022 northern hemisphere snow cover pattern is much different than the last two years (except Canada) as Eurasia was snowier, and North America (particularly the U.S.) was much less snowy. Interestingly, the December 2020-22 northern hemisphere upper air pattern is somewhat different from year-to-year despite presence of a cold ENSO climate. However, one similarity is the markedly anomalous cold stratosphere each of the past 4 months of December. The December 2019 northern hemisphere snow cover was remarkably similar to 2022.