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. Read the Hakuba Avalanche Bulletin provided by the Japan Avalanche Network.
2. Understand the International Avalanche Danger Scale.

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 Snow Density Storm Total Snow Depth Baro Pressure
20140303 Clear S < 1cm/hr ~ -3C 3C -3C 3cm 0mm 0kg/m3 3cm 147cm 923mbar
20140302 Overcast Nil ~ 0C 4C -1C 3cm 0mm 0kg/m3 3cm 144cm 917mbar
20140301 Overcast Nil ~ 2C 6C 0C 0cm 0mm 0kg/m3 0cm 144cm 922mbar
20140228 Overcast Rain - light ~ 4C 6C 2C 0cm 0mm 0kg/m3 0cm 150cm 923mbar

+ Check this page for some Hakuba backcountry first hand field observations from Japan Avalanche Network volunteer members.
+ For nice photos and other info, take a look at Hakuba MountainLife Magazine, especially the center fold
+ Follow my guiding and avalanche training business Facebook page for regular Hakuba backcountry comments and photos.

2014.02.28 Hakuba Backcountry Conditions Weekly Report

Besides summarising, I won't repeat anything that is already available in the above sources of info. Please read them, especially the avalanche bulletin. Seriously, if you are not reading the avalanche bulletin, then don't bother reading this either.

The last week:
The start of March - when every bite of your backcountry sandwich lunch leaves blood on the bread. 70 days in the backcountry completed, about 50 more to go. Cold air and not much new snow allowed for pretty safe and fast travel into some very good areas in the last week with great powder. Then that bit of snow on Tuesday saved the week with a fun 15-25cm at treeline. This new snow produced multiple small avalanches on a high pressure facetted surface with isolated patches of surface hoar being buried rapidly. I was working in an avalanche course for 5 days so my terrain engagement was limited to easy access areas, but people who put in the effort reported great times. To be honest, this season has been so good and so reliable for backcountry touring, and last week was just another week of the same. Temperatures rose way too much on Wednesday, and Thursday was grim light rain to perhaps 2000m, but that is quite normal for this time of year. In fact, it really only rained once all of Feb, on the 2nd. And that is pretty good for Nagano. Once again, February was very good for backcountry happiness this season (so was Nov, Dec and most of Jan)

Now:
Not so good, temperature and rain crusts to well above treeline can be expected along with a snowpack in a generally advanced state of settlement. New windslab from recent storm snow in the upper alpine, but when isn't there.

The next few days:
A warm weekend with possible light rain at valley bottom, snow at higher elevations, possibly a moderately significant amount by Sunday afternoon. Colder air returns next week, a hard freeze will set in as a more winter-like Siberian flow gets going, bringing the chance of consistent snow fall for most of the week, with the chance of a large load event arriving on Wednesday. So we have another melt-freeze crust with possibly associated facets to deal with. Once again, the least desirable scenario would be of the current wet warm surface to be buried wet and warm under a relatively thin layer of storm snow with much colder air above - this would produce a steep temperature gradient in the upper snowpack, leading to faceting at the crust. Ideally, the current wet warm surface would get a chance to freeze cold and hard before being buried. This could produce short terms instability on the slick crust, but a lower chance of developing into a longer term persistent weak layer as the crust starts to facet as described. Contrary to popular opinion, March is not the most stable month in Hakuba. March is when we have the most rain crusts, yet thinner [weaker] snow over them and yet still cold enough temps for faceting. So avalanches in March can be harder to anticipate than in January when the problems are mainly storm slabs and wind slabs with a sintering snowpack constantly growing deeper and deeper.

Remember:
March gets busy in Hakuba's popular backcountry areas every weekend. Watch out for people over head, and people below you. Don't follow other people's [usually terrible] skin tracks as it means your brain is disengaged from both the snow and the terrain. Consider avoiding Tsugaike's easy access backcountry area on sunny weekends when helicopters fly endlessly to dump anyone and everyone on Tengupara. It is very noisy and turns into a demi-ski resort.

Please, read the avalanche bulletin. By clicking on the danger rating graphic you can read important details in English regarding the specific avalanche problems and other vital data.

-damian