Why did this blizzard bring so much snow?

What can lead to one metre of snow falling in one dump? A huge contrast in temperatures, that’s what. That means winter and water in the same place.

In Jilin province, a cold part of northern China in any winter, recent temperatures have dropped to minus 21 Celsius. This is a month earlier than you might expect and shows the depth of cold in Siberia and northeast China.

So when a winter storm starts to spin up and this cold lump is dragged out from the frozen land, the storm is first invigorated by the Songhua River which, surprisingly, doesn’t freeze in the winter.

Then, like a train without brakes, an already vigorous storm rolls onto the Sea of Japan and is injected with yet more energy from the sea surface. Vast amounts of moisture are lifted into the air, frozen and blown out as snow.

The rapid deepening of this area of low pressure whips up giant waves. The storm that just hit Japan was the worst for a decade in Hokkaido and waves were recorded of ten metres on Thursday, whilst snow fell at a rate of 80cm in 24 hours.
 
Roads are still flanked by two metre snow banks but the skies are now clearer. A tidal surge – the dome of lifted sea in the middle of the storm – has caused flooding . Further snow showers are likely in Hokkaido but the storm has gone.

Snow fell as far south as Nagoya in southern Honshu – not a normal event. The next weather risk in the mountains is avalanche. The thaw may well cause flooding but Hokkaido, at least, remains cold.