A blizzard struck Northeast China in November 2020, and the maximum daily snowfall broke its record since 1961. The synoptic and climatic conditions and the predictability of this extreme snowstorm event are examined by using the daily National Centers for Environmental Prediction (NCEP) reanalysis and the second version of the NCEP Climate Forecast System (CFSv2). The results show that an anomalous anticyclone over Japan and an anomalous cyclone in South China supplied abundant moisture and the rapidly enhanced Siberian high triggered the snowstorm. Before the snowstorm, the positive North Pacific Oscillation (NPO) and North Atlantic Oscillation (NAO) were essential for the accumulated water vapor. In addition, we find that the monthly NPO index and NAO index in November 2020 are both extremely strong compared to 1979–2019, and their combination converges to create the extreme snowstorm-related atmospheric circulation. The positive NPO and NAO together induce an anomalous anticyclon