Off Piste Snow Report – N French Alps – week starting 11th March 2024
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A mixed and complicated week of weather ahead for the N French Alps. Cloudy days with snow showers interspersed with some great sunny days.
Most of the N French Alps should still see some light snowfall on Sunday (5 to 10 cm maybe), and light snow showers on and off throughout the week .
Natural snow depths above 2000 m are great, but not at lower altitudes. You can currently ski down to about 1400 m on many N facing slopes, but only to about 1800 m on S facing ones. Lower and mid-altitude resorts are really suffering from lack of snow, and their piste grooming teams are working very hard to ensure skiing for their customers.
High altitude areas in the E of the N French Alps, near the ridge bordering Italy, are currently (Sun 10th) benefiting from another ‘Retour d’Est’ phenomenon, which could bring a metre of fresh snow at the mountain tops, up to 20 cm of very windblown snow elsewhere, and big snowdrifts in leeward areas. This big snowfall will really only be affecting these very localised areas though.
Snow conditions vary wildly from day to day. They are currently very wind-affected in exposed areas, but when the wind calms down and fresh snow has fallen, they could be sublime! The best conditions are currently to be found on high gullies sheltered from the wind. With such a varied week of weather ahead, we simply need to take every day as it comes!
But even if the area near the French – Italien border are getting a bit more snow then area to the west again, there is at least some snow for everyone (see forecast below).
Still a lot of snow around there for some lucky resorts. Here's Le Fornet (Val d'Isère) on 10/03. The broken trees in the background are due to preventative 'avalanche blasting' by pisteurs only last week!
Avalanche Bulletin
For most areas in the N French Alps the current avalanche danger level is around a 3 out of 5. The high more N’ish facing slopes are the ones where the most avalanche instability currently is.
Any instability in the snowpack is going to be directly related to snowstorms. More snow = more instability. So it’s those areas near the mountain ridge with Italy which received a lot of snow on Sunday where danger ratings will be going up for the first 24 to 36 hours after the storm. This storm avalanche danger will concern all aspects on S’ish facing slopes as the sun and higher temps first hit them, and N’ish facing slopes due to the persistent weak layer that built up during the clear sky periods over the last 8 weeks or so.
After the instability directly related to the storm, the most unstable areas will be the N’ish facing slopes above 2200 m or so (the altitude where the rain/snow limit has been over the last week or so). The more rain-affected slopes below 2000/2200 m (due to higher temperatures) have become much more stable, as the snowpack has melted and refrozen (solidified).
The vast majority of avalanche accidents involve cold, dry slab avalanches. They’re almost always triggered by the victim (or someone in their group) on N’ish facing slopes (in the Northern Hemisphere) during December, January and February – even March, this year!
Weather forecast : Mon 11th to Fri 15th March thanks to Météo Alpes
A mixed week of weather ahead in the mountains. Days of cloud and snow showers interspersed with bright sunny ones. This will follow Sunday’s snow showers (very heavy for some areas near the Italian/French border like Val d’Isère, which benefited from another Retour d’Est)
MON 11th: A largely bright and calm morning with a few residual snow showers. Becoming more unsettled again in the afternoon with more snow showers, particularly for the W of the region (just up to 5 cm down to 1200 m or so). Light to moderate WNW wind. 0°C at 1500 m.
TUES 12th: Little change. Relatively cool, very mixed, cloudy weather in the mountains. A few very light intermittent snow showers down to 1200 m or so in the NW of the region. 0° C at 1500 m. Light W wind.
WED 13th: Turning fine and sunny. Feeling warmer, especially in the afternoon. Minimum temperatures between -2 and +2° C and maximum 12 to 16°C.
THURS 14th: Sunny with high cloud, especially in the afternoon.
FRI 15th: Cloudy with occasional snow showers down to 1500 m.
NEXT FEW DAYS: Continuing the same.
6 day weather forecast for Les Arcs by Snow-Forecast.com
Tip of the Week
Sun Shadow Slope Orientation
Since I so often talk about N’ish facing slopes (the vast majority of avalanche accidents happen on the North’sh side of the mountain – cold, dry slab avalanches triggered by the victim), and due to popular demand, I am posting this TOP TIP on using shadows to identify slope aspects (below). Also when any fresh snowfall arrives (as is forecast for the end of this week), high N’ish facing slopes are where the danger/sensitivity to triggers will be most prevalent.
SPECIAL HAT OFFER
1. To help you keep things acceptably safe off-piste and ski touring, I’m currently working on a pre-recorded online ‘Essentials Talk’. Here’s a sneak- peek draft: a ‘staff talk version’ of the Essential Talk, featuring an accident Prevention Framework, which I’m making available free of charge for a couple of weeks on my YouTube channel.
If you find it useful, please subscribe to this channel. There are lots of other cool vids in there too! Thanks again to Jérôme for the cover photo.
Safety is Freedom!
The post Off Piste Snow Report – N French Alps – week starting 11th March 2024 appeared first on Henry's Avalanche Talk.