Once Again, November 2023 Snow Cover Greater Than Normal

Table 1: Snow cover rankings during November 2023 compared with last year for various parts of the northern hemisphere within the 1966-2023 climatology.   

Discussion: The northern hemisphere snow cover during November 2023 was above normal (Table 1) which is consistent with each year since 2009. Climate Impact Company theorizes the reason for the consistent above normal snow cover just prior to the start of meteorological winter is due to cold advections snows across wide open water north of each continent and south of a constricting polar ice cap.

The northern hemisphere snow cover in November varied widely. Alaska ranked highest (6^th of 58 years) with much above normal snow cover while the continental U.S. was 16^th least snowy. The North American snow cover was slightly above normal (Fig. 1). Eurasia ranked 16^th most snowy (Fig. 2) and was the primary catalyst to the above normal northern hemisphere snow cover signature.

Last November, snow cover was well above normal throughout the northern hemisphere. North America observed their 3^rd snowiest November on record last year while the U.S. was 6^th snowiest. Interestingly, despite the much above normal snow cover leading into the winter season, the U.S. and Europe winter seasons were exceptionally mild (Fig. 3).

Fig. 1: North America snow cover anomalies for the month of November since 1966.

Fig. 2: Eurasia snow cover anomalies for the month of November since 1966.

Fig. 3: Northern hemisphere temperature anomalies for meteorological winter 2022-23.