The Last Week
Last week over a 2 day period, light snowfall built up 40-60m of light dry storm snow at treeline, depending on where you were in the valley. There really wasn't any significant avalanche events reported, with danger remaining at Moderate most of the time. Really only one thing stands out from the last week, and that was the conditions on a near white out day at Happo. It was empty, and depending on where you skied, it was overhead faceshot deep and dry on meaningful terrain. As one visiting professional guide said: "surreal". Then some wind arrived, along with the expectation for it all to go bad. But it didn't. On the 17th we had a morning of clear cool and calm weather, and Happo (plus other alpine areas) delivered "one of those days". Hope you didn't miss it, as you will seldom get a better combination of ski quality, weather and avalanche conditions.
Conditions as at Monday 18th, in the evening. Snowfall started again on the evening of the 17th as a low pressure moved by the SE of Japan. There was 25cm of dense upside down touchy new soft slab below treeline and at treeline and avalanche danger went up. As the low pressure moved NE past Tokyo, it dragged warm air north, and it is now raining to perhaps 1200m? This is of little concern since there is no good skiing at that altitude or below anyway. That warm spike will not last long as temperatures drop late tonight and the first of a few waves of cold snow arrives with a Siberian winter storm.
The Next Week
Significant change. The first intense precip this season from a cold Siberian flow storm arrives, and will remain active for numerous days. Snowfall will continue, sometimes intensely, sometimes light, until Friday. Then the longer term guess includes further periods of heavy snowfall on Sunday 24th and early next week. Valley bottom temperatures will be below zero the whole time, and at treeline between -10 and -15C. There will be wind. Avalanche hazard will go up, along with the risk of injury or death if you do not show patience, humility and a bit of respect for the nature of Nature.
The coming weather and avalanche conditions somewhat mandates below treeline skiing in the backcountry, and that is currently in a poor state in most areas with plenty of holes, waterways and small vertical features not filled in. The storm snow will eventually fill them to some degree, but before that happens, the storm snow will only hide those hazards from view. I'd be skiing BTL like it was early season, looking for early season hazards.
What has been quite enjoyable about this season is that when it snows, you notice and appreciate it. Not because we need it - sure, we do - but who cares about things you can't change? More so because you can see and feel the snowfall change the landscape with each small addition. Less is more. In a normal season, it snow so much and so often that yet another 50cm of new snow on top of a 400cm base becomes meaningless. The mountain landscape appearance does not change. More is less.
This will be the last weekly Hakuba backcountry update for the next month. Blame winter for being too short, and important mountain experiences too many.