Snow and Weather Data

For the preceding 24 hours to 7am at 800m elevation.  Hakuba backcountry snowpack and avalanche conditions below are used at your own risk, Click -All- to view entire season data.

Date Snow Depth 24hr New Snow 24hr New Snow Density 24hr New Water Equiv AM temp Max temp Min temp Precip type and rate Rain Altitude
20190216
156cm
1cm
~ ~
0C
2C
-2C
S < 1cm/hr
~
20190215
161cm
0cm
~ ~
-10C
-2C
-10C
Nil
~
20190214
166cm
13cm
49kg/m3
6mm
-5C
-2C
-5C
S 1cm/hr
~
20190213
164cm
11cm
46kg/m3
5mm
-3C
-3C
-7C
S < 1cm/hr
~
20190212
158cm
13cm
98kg/m3
13mm
-2C
2C
-3C
S < 1cm/hr
~

Hakuba Backcountry Conditions Summary

16 Feb 2019, AM update

Very good backcountry conditions in Hakuba above 1400m elevation, particularly shaded slopes above 1700m. There is  more snow closer to the coast at lower elevation - the coast has had a classic week!

Outlook

It is snowing again today, and tomorrow will be great. And then winter moves higher in elevation for a while. There is southerly tropical air and rain coming Tuesday-Wednesday, then a small burst of northerly snow immediately following that. Then not much. The big picture is a 1-2 hit sequence of warm air injections from the south next week, the second one possibly coming next weekend may go well up into Hokkaido. That is all long term and big-picture, it may change.

Avalanche Hazard

At about 2000m: New snow today will increase hazard a little in the higher elevations with new storm slab and windslab forming by PM . But it probably isn't going to snow that much. 

Snowpack Discussion

One big widespread rain crust all the way to perhaps 2400m was formed on the 3rd of Feb and buried on the 4th, so lets call it the Feb 4th rain crust, the date of burial.  Almost no one is talking about this old layer, which is sometimes a good reason to be talking about it. The crust is not so deep, 40-120cm depending where you are.  I can not offer any direct information as I have not been skiing much in the Hakuba area for some time now. The snow above the crust loaded slowly over a week-long period. We are now reaching a more critical load amount, but perhaps in that time the crust bonded well with the snow immediatley above. Or maybe there is a weak layer hidden down there with the crust in the form of facets. Overall, it has been a quiet crust in terms of avalanche activity, but that may be due more to the slow period of gradual loading. The next event I'll be watching is how the snow above the crust reacts to the stress plus load of warming and rain next week.

Official JAN Avalanche Bulletin

You should read it, but be aware that on some days this bulletin is not so accurate.  Visit the Japan Avalanche Network at www.nadare.jp. Their website is not well designed, so take care finding the info you need - it can take a few clicks to find the full bulletin, not just a summary. Their site doesn't work perfectly in some browsers. Make sure are you reading the bulletin for Hakuba, and for the current date. It is not in English, yet it is the only bulletin in Japan. Significant limitation - VERY IMPORTANT: due to Japanese forecasting laws, the JAN avalanche bulletin is only a statement of estimated conditions at 7am. It does not include changes to the avalanche danger that may occur during that day due to changes in weather. This makes it dangerously inaccurate on days when there is rain in the forecast for midday, or a rapid rise in temperature, or very rapid new snow accumulation.

The info on this page is intentionally brief. Use at your own risk.

Note on the data

This data is collected daily between 6am and 8am for the previous 24 hours at 800m in Ochikura near Tsugaike ski area. It is part of the daily risk management process in our backcountry guiding operation. Our weather station is in an area that receives more snow than the same altitude further south in the valley.

Rain Altitude is given if it rained at anytime in the preceding 24h hours. Sometimes it is an estimate, other times it is based on observation. In December you should always assume there is a shallow early season rain crust above treeline elevation.

Season Comparisons

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