This personal blog contains snow, avalanche and weather data along with weekly commentary that may be useful in planning your Hakuba backcountry outings.

More important than anything else

1. Hakuba Avalanche Bulletin by the Japan Avalanche Network.
2. Understand the Avalanche Danger Scale.
3. Know what the avalanche problem is and how to avoid it.
4. Carry beacon, shovel and probe in the backcountry. Know how to use them.

Other useful info

For avalanche courses and backcountry guiding in Hakuba please visit www.mountainlife.jp. For 10 seasons this blog has provided valuable info without a single ad nor any payment. Please support us.

Recent weather data recorded at 6am each day for the preceding 24 hours. Altitude 800m.

Date Cloud Cover Precip type and rate Rain Altitude 6am temp Max temp Min temp 24hr New Snow 24hr New Water Equiv 24hr New Density Storm Total Snow Depth Baro Pressure
20170122 Broken Nil ~ -7C -2C -8C 20cm 17mm 86kg/m3 38cm 156cm 916mbar
20170121 Obscured S 1cm/hr ~ -3C -2C -1C 24cm 21mm 101kg/m3 24cm 151cm 917mbar
20170120 Scattered Nil ~ -9C 0C -9C 1cm ~ ~ 6cm 132cm 914mbar
20170119 Overcast S 1cm/hr ~ -2C 0C -2C 6cm 5mm 85kg/m3 6cm 142cm 922mbar

Hakuba Backcountry Weekly Snowpack Summary

THIS IS NOT AN AVALANCHE BULLETIN. I WILL BE WRONG SOMETIMES. I WILL NOT KNOW IMPORTANT THINGS. IT IS INCOMPLETE. IT MAY QUICKLY BECOME OUT OF DATE. I AM NOT AN EXPERT AND FEW PEOPLE ARE.

I'll update this rolling summary of the weather and consequently the snowpack every week - I'm too busy and unpaid to do it more often. I'm attempting to divide the summary into elevation bands. This makes it more difficult, but Hakuba has a backcountry elevation range of about 2500m. That is a lot of terrain vertical scale and the snowpack develops very differently in each elevation band as the season un-winds, and winds-up. This is the kind of avalanche info I would want if I were going to another place to backcountry ski in avalanche terrain.

Use at your own risk. If you die, it is your fault, not mine.

Who am I? I'm damian, owner of Hakuba MountainLife, local backcountry guide. Ten years in Hakuba's backcountry. Member of the Association of Canadian Mountain Guides in the backcountry ski guide stream. Professional Member of the Canadian Avalanche Association. Professional Member of the Japan Avalanche Network. Instructor of over 55 Avalanche Canada AST1 and AST2 courses. [This info is provided so that you can verify if you want to trust me or not. The listed organizations do not endorse anything on this blog.]

FINALLY... please remember the "Avalanche Triangle". On the sides of the triangle are three important elements of avalanche risk management: Terrain, Weather, Snowpack. In the center of the triangle is the the fourth element, the Human Factor (briefly, your personality). This weekly summary is about the snowpack. Only one of four elements, and the least important. Master the others.

Hakuba Backcountry Snowpack Summary as at 2017.01.17

Very quick update, too busy.

+17th: First sunlight after storm, warmer. Size 3 natural avalanche south Happo.
+18th: Natural avalanches size 1.5-2.5. Clear cold night produced surface hoar. Buried in afternoon.
+19th: Natural size 2.5 avalanche on Norikura-dake. Settlement and suncrusts.
+20th: Some more surface hoar buried
+21st: A lot of new snow, with cracking and small avalanches in new dense storm layer.

Bottom line: different avalanches types and sizes at different elevations all week. Current uncertain distribution and sensitivity of buried surface hoar ahead of more loading.

Ski quality of note: lots of good backcountry skiing.

If you would like to comment, please do so on the relevant post on the Hakuba MountainLife Facebook page www.facebook.com/mountainlifejp

The Japan Avalanche Network avalanche bulletin for Hakuba is available here. www.nadare.jp. IMPORTANT!! Please understand very clearly that it is fundamentally different to avalanche bulletins in other countries: it is only a statement of expected conditions as at 7am. It is NOT A FORECAST of expected hazard over the day. YOU need to judge whether increasing temperature, rain, heavy snowfall, intense solar radiation or wind will increase the avalanche hazard as the day progresses. This is not ideal, but there are genuine and challenging Japan-specific reasons for this limitation.

Below Treeline (BTL). 400-1900m band

  • Most recent snowfall was 50cm on the 21st
  • Possible lingering upside down storm snow.
  • Buried surface hoar from the 19th about 50-70cm deep
  • Still scrubby in some areas
  • Dangerous glide cracks are opening and some may fail as full depth slabs on low elevation sunny slopes

Treeline (TL). 1800-2100m band

  • Last snowfall 21st = approx 80cm.
  • Windslab on the surface
  • Possible lingering upside down storm snow.
  • New fragile cornice growth
  • Buried surface hoar from the 19th about 70-100cm deep

Alpine (ALP). 2100-3000m band

  • Large avalanches continue
  • Significant wind distribution and windslab.
  • Is is impossible to comment on the deeper details of the ALP snowpack.

Remember that in the ALP, the snowpack is far more variable, harder to interpret reliably, and avalanches are bigger when you get it wrong. Conducting stability tests in the ALP is generally not recommended due to these factors. If you do conduct stability tests in localized areas, then ignore all "stable" results! You may be 10 turns away from dramatically different stability.

The next few days

A cold burst of moderate snowfall from a disturbed Siberian flow will start night of the 22nd until the night of 24th. More powder skiing.

Read the avalanche bulletin (see link and comments further up page). Also listen to Doug at Tsugaike

Look for signs of instability. If you get some avalanche surprises with the coming new storm load, step back from the terrain. We all get surprises, and they mean we are wrong. Donald Trump would never admit to being wrong, but he is not a backcountry snowboarder or skier managing avalanche risk. You, however, are. So be humble and adapt to surprises. DT wouldn't last a friggin week out there. But you can last a lifetime of powder skiing with no tracks if you want to.

Seasonal Comparisons