23 Jan - problems?

Out today I have to admit that there are places looking very lacking in snow, or at least avalanche debris. Gullies are still deep and v shaped, stream holes are open, and scrub is sometimes everywhere. We went to 1900m where the wind was gusting to 40-50kph from the north and transporting snow onto south aspects, creating some small soft cornices and also loading a potential problem layer. We have a thick sun crust from recent clear weather, above that is 10-15cm of dry loose powder, above that is another sun crust from yesterday. So that is a very soft layer sandwiched between two much harder layers. That soft layer has the potential to remain preserved as it is protected from further wind and sun from the upper crust. One of the classic avalanche problems in Hakuba is preserved stellars as a weak layer. Well, we appear to have that in the making, and worse is that it is above a hard crust that may or may not have surface hoar on it, and protected by another sun crust op top. You'll find this crust-powder-crust sandwich on solar aspects up to at least 1900m. If it gets buried by new snow and additionally loaded with wind, we may have a problem. If you are not looking out for it on south and east aspects as this coming storm arrives, you should stay in resort.

Northern aspects have been wind scoured and old tracks are now showing in the scour well down below ridge lines. Localised variable winds in tight terrain well below tree line has created thin areas of wind slab sitting over unconsolidated powder above a temperature crust. I saw long shooting cracks on a 40-45 degree slope today, despite the fact that it was well BTL and we had no significant snowfall in the last 48 hours.

And don't forget skiers started to trigger slab avalanches yesterday at 2100m on ENE and NE aspects. It didn't help that they went straight for the obvious trigger point in the start zone - in this instance a convex roll. It is amazing how unaware some people are.