On the cold wave of January 1954 in the Far East

Summary A synoptic study is made based primarily on 10-day and 5-day mean maps on an unusually cold spell which appeared all over the Far East in the end of January, 1954, following an abnormal warmth. It is found that while it is warm in Japan, cold air is accumulated in Siberia to the north of the climatological jet stream and is confined in the northern latitudes by the latter as long as the high index pattern prevails. But once the index drops, with the southward displacement of the jet stream, the permanent trough of the Far East deepens and the cold air so far accumulated is allowed to penetrate into southern latitudes. Some characteristic features of contour pattern and frontal activity preceding and following the cold air outbreak are described. Further, it is shown that the blocking wave directly related to the cold air outbreak in the Far East can be traced from as far east as North America or possibly the eastern Atlantic.