This morning it is a beautiful clear and sunny day, a perfect way to end the long weekend. The conditions that you can expect on the slopes are variable, from nice corduroy on the groomers, packed powder and chopped powder on the edges of the runs and still some nice lines to be found through the trees. The light snow that we had yesterday has settled and we can expect some more tomorrow, starting with light snow fall on Tuesday and by Wednesday it will be getting heavier.
Today is the last day of the long weekend and so resorts will still be busy today, getting quieter towards the afternoon as everyone starts heading home. You can expect some lift lines, but waiting time will not be long.
The sun today will be taking temperatures up slightly by midday, so it will be a nice warm day, however, this will also cause some snow melt which will freeze as soon as the sun starts to go down. In the late afternoon watch out for icy patches in shaded areas. From tomorrow temperatures will drop back down to below zero and continue dropping throughout the week.
The recent storm of 100110 came in from the North West in the middle of the night with little wind before winds shifted and came in from the South west with constant moderate force from 11:00 and strong gusts at all elevations through out the day. However at ridge top and in the Alpine winds were a more constant strong from the South West. Snow fall was between 2 and 3 cm per hour during the storm and by the end of the 18 hour storm 40 cm of dry new snow had accumulated in the Tsugaike area at 1700m. The new snow was accumulating on top of the previous days sun crust and evening surface hoar that had formed on south slopes, North and West slopes did not see the formation of the sun crust but tests on 110110 showed signs of buried surface hoar from the 090110 early evening pre snow fall in the early hours of 110110.
Slab avalanches reported running natural on the steep North aspect of Wakagurimine, Otari in the afternoon of 100110 during the hight of the storm. Today’s clear weather gave clear views of the skier triggered wind slab, size 2 on the East face of Norikura Dake. The crown fracture could be seen just below the cornice high up on the prominent East face just climber’s right of the summer trail. There has been a lot of stored energy and tension in the new snow due to rapid accumulation and intermittant moderate and strong winds and thus shooting cracks have also been observed both during and post storm. Debris from multiple size 2 loose naturals during the storm on the east faces of Yamakami no One were also observed today. Most of these stopped mid or bottom of track.
Tests in the Tsugaike area during and post storm found the weakest layers at the new snow / crust or new snow / buried surface hoar interface down 15 ~ 25 cm on Southern and Northern aspects. The N aspect snow pack has multiple faceted layers with in the upper 50 cm in both the new snow and past storm snow. An AK block 3 SP released with in the old storm snow at 50 cm. ECT M at 40 cm from surface with 50% propagation was also observed in the same location on the North aspect of Hiyodori west saddle; 1900 m.a.s.l.
Be extremely cautious in the Alpine with travel on lee slopes and cross loaded slopes in the Alpine not advised. There were continued strong winds at ridge top all day 110110 with moderate snow transport to the east facing slopes. Use caution on lee slopes and cross loaded slopes at Tree Line on steep and convex terrain. Be aware that there are definite wind slabs with stored tensile energy still waiting to release. Take due caution also around cornices as they are still fragile and getting bigger by the day.
Most treed areas below tree line have been quick to stabilize and are still good riding on the northern aspects. Do be careful of large tree wells and steep convex slopes, entering open glades and exiting on to cat road cut banks as there is still a possibility of rider triggered slabs in steep terrain.
ALPINE: High with continued strong winds ( lee slope loading)
TREE LINE: Considerable ( lee slopes)
BELOW TREE LINE: Moderate (watch for day time warming and solar radiated slopes)
Official resort snow depths on 11th Jan 10:
335cm (Alps daira)
Sun Alpina Sanosaka: