Winds from the frozen tundra, gusting to over 100kph, have brought nearly a metre of snow to northern Japan, with more falling now and more to come.
When the wind blows cold in Siberia, it is no great surprise, but when that wind is particularly cold and it blows out over the Yellow Sea and the Sea of Japan, the results are dramatic.
In the ice carving city of Harbin, the temperature peaks at -20C. Further downstream, on the coast, sits Vladivostok with a slightly less cold -16C as a brief afternoon maximum. Beyond here is the Sea of Japan…
The Sea of Japan is surprisingly warm even now. In the north, in the bay beside the whisky distilling town of Yoichi, you can measure 10C. That means that there is a sudden warming of this Siberian blast of wind by at least 26 degrees as it blows over the water.
Big temperature differences mean big weather and the resultant snow, still falling in Hokkaido, trapped over a thousand people on a train on Sunday.
Nearly 300 flights have been cancelled or delayed on Wednesday as snow ploughs struggle to clear runways and roads. They are fighting a losing battle for the time being.
The two sources of really cold air in the northern hemisphere at the moment are Siberia and Greenland. Siberia will give Japan a good start to the skiing season and Greenland will supply Scandinavia with snow.
The deep snow in Hokkaido contrasts starkly with the scene in the European Alps. Here it is still not cold enough for any significant snow and the lifts hang forlornly over green, not white.