Off-Piste Snow and Weather 21 – 29 March 2019


For Savoie and the Northern French Alps

Hoping for smooth spring snow skiing!

A high-pressure weather system is now in place over the N French Alps, bringing dry sunny conditions until the end of March

The avalanche danger rating is down to 1 below 2500m and 2 in some places it is likely to remain that way until we see significant warming or new snow. There are a few slabs on high N and NW facing slopes above 2500m.

With this nice sunny weather ahead we’re hoping for lovely smooth ‘spring snow’ conditions to come into place very soon. They’re already appearing on sunnier slopes at low altitude, but we could do with some more intense heat in the day followed by good overnight refreezes for the lovely smooth conditions to become more widespread! Fingers crossed!

Off Piste Snow & Weather: 21 - 29 March, Savoie / N. French Alps
Smooth spring snow. H Schniewind photo from last April

What we mean by ‘spring snow’

We’re talking about the lovely smooth, soft snow that occurs in spring after a few melt-freeze cycles. Not the thick afternoon slush or rock hard morning snow that we also find in spring! Off-piste spring snow is one of the best things that the Northern French Alps has to offer. With lift access to all slope orientations: east, south, west and then north, you can find it and have fun with little effort.

Melt-freeze cycles

Following a few successive proper ‘melt-freeze’ cycles, or after a snowfall, the top snow layer begins to form a crust that gets deeper and stronger after each melt, allowing free water to drip down and re-freeze during the night. (A melt-freeze cycle is where the snow melts during the day and then freezes at night – that’s one melt-freeze cycle). 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. This 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. It softens as the day goes on as it melts in the warm sun and increased temperatures. The process starts on east facing slopes which receive the sun first. It moves onto the south, then the west facing ones, following the sun’s movement. (North facing slopes at 2500+ metres don’t normally get a melt freeze layer until late April, due to lack of sun).

Top tips for spring snow skiing

After a couple of good melt-freeze cycles have created a solid layer on a slope, the trick is to get on 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 so, e.g. an east facing slope at 9 or 10 am.

After a solid melt-freeze layer has formed and there’s been a good daytime melt, 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, with a minimum of –2° C (preferably lower) at 2000 m if you’re going to be skiing at this altitude and above. This will allow the melted parts of the layer to freeze solid again and pretty much guarantee that it will support your weight the next day.

So get on the east facing slopes, which get the sun first, as soon as the lifts open at 9 am. Then you move to south facing slopes, then west. Do this right and get some of the best skiing of the season.

You need to get off those slopes when the snow surface begins to get too soft and mushy or you’ll start breaking through. It’s important not to ski these slopes when they become soft and mushy because :

  • It’s dangerous for your knees.
  • The slope may become unstable due to all the melting. Then avalanches can be a problem on these sunny slopes.
  • You will leave nasty ruts in the snow which will ruin its quality for everyone who wants to ski it the next day.

Off-piste weather forecast for 21 to 29 March

Sunny day, softer in the afternoon.
There is little or no morning greyness in the lowlands and valleys, but frost to the plain.
Some fine clouds high at the end of the day.

Highest Temperatures (Slope South): , 9 ° C to 2000 m, 0 ° C to 3000 m.

NIGHT FROM THURSDAY 21 TO FRIDAY 22
More or less well starry.
The fine, high clouds become more numerous at the beginning of the night, barely dense, then move away after midnight.

Lowest temperatures -6 ° C to 2000 m, -8 ° C to 3000 m.

For the day and the night:

At 3000 m, this locally moderate wind this morning, becomes strong in the morning, more moderate in the afternoon, then weak at night. Strong gusts (more than 60 km / h) from Foehn-Lombarde in the morning on the Italian borders, as well as downwind of the high ridges and passes of Beaufortain, Est Vanoise, Maurienne to Belledonnes, become less strong. afternoon and night.

FRIDAY 22
Another beautiful sunny day, warmer in the afternoon.

Night more or less well starry. Some passages of fine clouds very high, barely dense.

Isotherm 0 ° C rising everywhere around 2900-3000 m during the day, 2900-3100 m at night.
Isotherm -10 ° C: 4500-4600 m.
Wind at 2500 m: ENE at SE 10-30 km / h.
Wind at 3700 m: East at ESE 20-40 km / h, then 20 km / h at the end of the night.

SATURDAY 23
Always good weather with a foehn wind weakening at 40/50 km / h and an isotherm 0 to 3000 meters.

SUNDAY TO THURSDAY
The high pressure continues. The temperatures remain spring like reaching 9C at 2000m and OC at 3000m. The sun continues to shine.

Meteo France are on strike to protect the Bourg St Maurice weather and avalanche forecasting office.

Tip of the week

Learn how to ski the lovely smooth spring snow correctly for maximum enjoyment by following our advice above.