Off Piste Snow Report – N French Alps – 10th April 2023

Off-piste snow depths for the Hte Tarentaise area of Savoie from Meteo France 08/04/2023

There’s currently (Sunday) still a little winter powder snow still around on high N facings slopes. Also in the warm sunshine, lovely spring snow conditions are  now coming into place on most S facing slopes and on N facing ones below around 2000 m. The snow is changing very quickly, and you need to get your timings right to enjoy it to the maximum.  Spring snow transformation happens very quickly after snowfalls at this time of year, so even if it snows, the following info on how to make the most of these lovely spring snow conditions is all relevant.

Melt Freeze Cycles

When cold dry snow melts in the sun/heat during the day and then freezes at night that is a “melt-freeze cycle”. Once that occurs several times in succession, the top snow layer begins to form a crust that gets deeper and stronger after each melt allows free water to drip down and re-freeze during the night. Any given ‘melt-freeze’ layer becomes stronger with each cycle of melting and freezing due to the deeper penetration of each melt during the day, which then adds more depth to the potential frozen layer at night.

If untouched, the top of this frozen layer is smooth and solid first thing in the morning, then it becomes progressively softer as the warm sun and increased temperatures melt it as the day goes by. This process starts on East faces because they get the sun first thing in the morning, then South, then West. (North faces at/above 2500 in the metres in the Alps don’t normally get a melt freeze layer on them until late April due to lack of heating from the sun. But once they do, you can ski well into the afternoon after a good freeze at night).

For good spring snow skiing:

The trick is that after a couple of good melt-freeze cycles have created a solid layer on a slope, you need to get onto that slope when the snow surface is smooth and solid with only 2 or 3 cms of soft melted snow on top. (These are generally slopes that have been in the direct sunlight only for an hour or two  e.g. an East facing slope at 9 or 10 am).

Then you need to get off those slopes when the snow surface begins to get too soft and mushy or you’ll start breaking through, which is dangerous for your knees. AND the slope may be unstable due to all the melting – then avalanches can be a problem on these sunny slopes from the lack of stability due to melting of the bonds between snow crystals and snow layers.

See our tips at the bottom of this blog for more on how to get the most out of your spring snow skiing.

Avalanche Bulletin

The current avalanche danger is a “moderate” 2 out of 5 on the colder N’ish facing slopes above 2300 m virtually throughout the N French Alps, and a “low’ 1 out of 5 on the lower slopes.  

The snowpack is generally pretty stable except for small instability on those colder high altitude, mainly N facing slopes where a persistent weak layer(s) of unconsolidated ‘sugary’ snow has developed, particularly during the cold clear nights, There is a chance that skiers on these sort of slopes could trigger a slab avalanche.

With only minimal fresh snow forecast this week, we suspect that these avalanche danger ratings will probably stay the same next week.

Natural avalanche activity will  be taking place as the day warms up and the snow humidifies, particularly on the steep sunny slopes.

Weather forecast 10th to 14th April onwards

A mixed week of sunshine, cloud and occasional light snow showers in the mountains. 

MONDAY 10th April: A sunny morning in the mountains, particularly in the E. Thin high cloud will thicken in the afternoon. 0° C at 2600 m. Light to moderate N wind.

TUESDAY 11h April: Cloudy with possible light sprinklings of snow above 2000 m in the N of the area (N Savoie & Haute Savoie). 0° C at 2300 m. Light to moderate WNW wind.

WEDNESDAY 12th April: A sunny start to the day. Cloud coming in later with possible snow flurries overnight.

THURSDAY 13th: A cloudy morning with a few residual snow flurries. Brightening up  later.

FRIDAY 14th: A clear morning, but again clouding over later with possible snow showers in the mountains.

SATURDAY 15th April onwards: Changeable.

Tip of the Week

To make the most of spring snow skiing:

After a solid melt-freeze layer has formed and there’s been a good melt during the day, it needs to freeze well the next night in order for it to be right for the next day. The ideal is a cool clear night, e.g. minimums of –2° C or lower at 2000 m, if you’re going to be skiing at 2000m and above. This will allow the melted parts of the layer to freeze solid again from that altitude up, and that will pretty much guarantee that it will support your weight the next day.

Then, in the morning, you look to get on the East facing slopes first thing, 9 am, because the sun rises in the East and therefore those slopes get the sun first. Then you move to South facing slopes, then West. Do this right and get some of the best skiing of the season.

Aside from a night that is not cool enough, the only thing that gets in the way of great spring skiing is the nasty ruts in the snow that people leave behind because they either ski spring snow slopes before the melt-freeze layer has formed, too soon after a snowfall, or they ski the slopes too late when they’re too soft and mushy.

“Safety is freedom”