There’s been a great drop in temperature over the last week and freezing temperatures continuing today with some nice powder to be found for those in the know yesterday. Hints of snow though nothing in the valley this morning, but snow forecast next week along with cold temperatures so conditions should be looking good for the rest of January.
Forecast:
Cloudy/Sunny over the weekend with more snow through next week
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TEMPERATURE IN THE VILLAGE:
-2 degrees C.
TEMPERATURE AT TOP OF MOUNTAIN:
-5 degrees C.
WIND:
Light to Moderate North-Westerlies
VISIBILITY:
Varying through the day.
LIFT OPERATION:
Goryu Toomi, Hakuba 47 the Gondola, Happo-One, Tsugaike Kogen, Iwatake, Cortina, Sanosaka, Sun Alpina, open.
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Backcountry Travel Advisory:
There has been a lot happening in the mountains lately. We had rain to 2400 meters through the night on January 11th that turned to snow on the morning of January 12th. That snow fell hard in the AM and tappered off in the afternoon. Cool temperatures through the night of the 12th made everything crisp and turned the rain layer into a hard ice crust. The morning of the 13th brought strong cold winds and more snowfall out of the North West that scoured the Northern slopes and deposited large amounts of wind affected snow on the Soutern slopes. This wind deposited snow rested over the rain crust of the day previous and although bonding faily well at low elevation below tree line the wind deposited snow has not been as quick to bond at tree line and in the Alpine areas of the Hakuba Mountains.
Use extreme caution when moving on or under South and South East aspects at tree line and in the alpine as unstable wind slab is present on these slopes. Be aware of solar radiation on these slopes today and temperature increases.
The wind slabs that were created on the 13th remain unstable and are not bonding to the ice crust below them. One large Size 3 avalanche from the peak of Hakuba Norikura Dake was observed and investigated by students on a recent Advanced Avalanche Awareness Course. The crown fracture was an average of 70 cms over a width of 200 meters and ran close to a kilometer to it’s run out on the flats of the Tsugaike shizen. There were massive blocks of high density wind slab and debris that was piled 5 meters deep in places. The avalanche is presumed to have happened in the early hours of January 14th.
Field Tests:
Snow profiles showed that the wind slab found on the South Eastern aspects of the Tsugaike area are over-riding a lower density layer of new snow composed of needles and decomposing snow that has started to facet right above the ice crust of Jan. 12th. Moderate; sudden colapse, compression test results were found as well as a Reusch Block 4 on the same Ice crust / new snow interface that reconfirmed the instability of the newly created wind slab.
Clear skies and cool temperatures overnight will have only continued to decrease stability with increased faceting at the ice crust new snow interface.
Forecast:
Be increasingly careful as new snow that is forcasted this week acumulates on north facing wind scoured slopes, that may have a layer of surface hoar on the crust after last nights clear skies, will not be stable and should not be ventured on to with out reasing there stability.
Wind-slabbed south slopes with increased weight of new snow may produce large destructive avalanches and large alpine bowls and non-supported slopes should be avoided.
Hazard:
Above tree line: Considerable
Tree line: Moderate
Below tree line: Low
See Below for International Danger scale classifications or click on the Canadian Avalanche Association web page for the International Danger Scale.
Low:
Natural avalanches very unlikely. Human triggered avalanches unlikely.
Travel is generally safe. Normal caution advised.
Moderate:
Natural avalanches unlikely. Human triggered avalanches possible.
Use caution in steeper terrain on certain aspects.
Considerable:
Natural avalanches possible. Human triggered avalanches probable.
Be increasingly cautious in steeper terrain.
High:
Natural and human triggered avalanches likely.
Travel in avalanche terrain is not recommended.
Extreme:
Widespread natural or human triggered avalanches certain.
Travel in avalanche terrain should be avoided and confined to low angle terrain, well away from avalanche path runouts.
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Happo-One:
BASE DEPTH: 75 cm(at the base); 240 cm(at 1500m)
Goryu/47:
BASE DEPTH:80 cm(at the base); 275 cm(at 1500m)
Tsugaike Kogen:
BASE DEPTH: 110 cm(at the base); 245 cm(at 1500m)
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