Off-Piste Snow and Weather 14 March 2019


For Savoie and Northern French Alps

More snow for the next few days makes it complicated!

There are a few more unsettled windy days ahead, with a lot of fresh snow especially on Thursday night. There should be a sunny day thrown in on Saturday! From the middle of next week, it should become calmer and sunnier.

There is a general avalanche warning for Thursday night and Friday with possible spontaneous avalanches affecting the mountains and even some roads due to heavy snow and rising temperatures. From what we have observed be very wary on Friday both on high and north facing slopes where there will be slabs of cold dry snow on a series of weak layers where a skier can trigger an avalanche and lower down on slopes affected by rising temperatures whihc could release spontaneously.

On Saturday with temperatures rising rapidly in the sunshine be concerned about slopes facing the sun and direct action avalanches that might happen.

In general we have found that there are three zones to think about in the mountains right now.

North facing slopes above 2300m where there have been few skers this season have svseral weak layers and fresh snowfall will be very unstable both during for 48 hours after the snowfall has finished

North facing slopes in lift accessed off piste with a lot of skier compaction. In these cases the fresh snow will be unstable for 48 hours after snowfall but it is sitting on a more stable base. It is the top layer that could release

South facing slopes everywhere especially below 2400m will release spontaneous avalanches due to rising temperatures, these could affect skiers and roads anywhere.

Off Piste Snow Report 14 - 22 March 2019
Searching for the best off-piste snow. Wayne Watson photo

Last week was wild with high NW winds and fresh snowfall (often not as much as predicted, but usually between 5 and 15 cm at a time). The wind blew the snow all around the mountain, scouring it off altogether in places. We’ve found some very nice accumulations in gullies and sheltered spots, and windslab forming in more exposed areas.

Even when expectations have been low, we’ve been finding some remarkably good skiing in the fresh snow. Visibility has been tricky at times, and will continue to be for the next few days. It’s often meant we’ve had the mountain to ourselves, and have spotted some wonderful wildlife.

Off-Piste Snow Report 14 - 22 March 2019
Large chamois herd we spotted. Wayne Watson photo

Snow stability over the next few days really depends on the quantities of snow that we get. The amount predicted in the forecast and how much we actually receive can be two very different things. Any fresh snowfall of more than 25 cm could cause things to become very dangerous during the snowfall and in the next 24 to 48 hours after it.

Pay attention to avalanche bulletins and look out for any recent accidental avalanche activity, i.e. avalanches that have been triggered by skiers. Recent avalanche activity is the mountain speaking out, and showing you that things can be dangerous! When you see recent accidental avalanche activity, focus on the aspect and altitude of the slope and avoid similar slopes unless you really know what you’re doing.

As well as reading reports in the bulletins for your area, and looking out for your own evidence, another useful source of information of recent accidental avalanche activity is word of mouth. When anything happens, people are bound to be talking about it, so listen out.

In many places on high cold North’ish facing slopes above 2200 m cohesionless ‘sugar snow’ that we keep talking about still persists. Fresh snowfall keeps hiding that fragile layer, but it was exposed again only a couple of days ago before the snow fell.

There’s a huge difference between well-travelled off-piste areas where the weak layer’s been well compacted (effectively ‘neutralised’) by skier traffic, and those less travelled off-piste areas which haven’t received the stabilising effect of skier compaction. It’s important to be aware of this difference even when just traversing on high steep North’ish facing slopes above 30° to 35° which are less skied. (That’s the steep part of a black run). Be especially wary if you’re ski-touring in areas which haven’t been subjected to much skier traffic/compaction.

Off-piste weather forecast for 14 – 22 March

DAY OF THURSDAY 14
In the mountains, temporary some visibility. This afternoon: precipitation becoming continuous and strong, more slowly in Haute-Maurienne. Fog, strong wind at high temp.
Rain-snow limit that can remain around 700/900 m with wet snow until around 1500 m.
Around 2000 m about 20/25 cm.10 / 15 cm Haute-Maurienne
around 2000 m -4C, around 3000 m -10C.

NIGHT FROM THURSDAY 14 TO FRIDAY 15
Abundant snow from around 1000 m in the middle of the night, then 1300/1500 m late at night with wet snow until around 1800/2000 m.
Big storm, snow layer very irregular, on average around 2000 m 40/60 cm.
Wind around 2500 m northwest 50/80 km / h, around 4000 m northwest 100/150 km / h.
Minimum temperatures:around 2000 m -4C then 0C.

FRIDAY 15
Alot of showers with clearings a lot of fog. rain-snow limit around 1800/2200 m, 0C degrees around 2300/2500 m. High risk of persistent spontaneous avalanches.
Wind at 2500 m: North 40/60 km / h weakening in the afternoon.
Wind at 4000 m: north-west 100/120 km / h.

SATURDAY 16
Very sunny. Temperatures around 2000 m from -1C up to 8. Isotherm 0 ° C rises 3200 m.
Weak northwest wind in mid-mountain, high north-west still quite strong.

SUNDAY 17 AND MONDAY MARCH 18
Sunday It will snow in the mountains around 1000m. At the front, the sky will gradually cloud over. Unstable weather will settle down with more showers in the northern third of the Savoie in the afternoon.
Monday, the sun will dominate the regions closer to the Mediterranean. Elsewhere the weather will be variable with mostly scattered thunderstorms and showers.
On Sunday, the westerly wind will be strong. The Mistral and the Tramontane will settle in their domain and will be moderate.

TUESDAY 19 AND WEDNESDAY 20 MARCH
Clouds and beautiful clearings will share the sky.

THURSDAY 21 AND FRIDAY 22 MARCH
A calm and dry weather should concern the country, generally sunny with some local morning greyness.

Tip of the week

Pay attention to the avalanche bulletin for your area and look out for any recent accidental avalanche activity. Focus on the aspect and altitude of the slope that avalanched, and avoid similar slopes unless you really know what you’re doing.