Off Piste Snow Report – N French Alps – week starting 18th March 2024
A mild and largely sunny week in the N French Alps, with a few snow showers at high altitude on Monday. Feeling very spring-like.
Snow conditions in N French Alps will be very variable this week, with mild temperatures and plenty of sunshine. A few snow showers above 2400 m or so at the start of the week, but rain at lower altitudes. As long as there are a few successive days of warm sunshine and clear nights, causing ‘melt freeze cycles’ * we wouldn’t be surprised if ‘spring-snow’ conditions** don’t start to appear towards the end of the week! For the moment though, the snow is very much in ‘transition’ between winter and spring snow due to new snow, poor overnight refreezes and limited snow melt during the day.
Even when a few cm of fresh snow has fallen at high altitude, things are warming up quickly and becoming heavy to ski – even by mid-morning. Needless to say, off-piste conditions are currently rather tricky. If you get it right, it’s great. Get it wrong, it’s really bad!
Best snow coverage remains in the higher altitude resorts, particularly over 2200 m, where it’s been snowing rather than raining. Unfortunately, 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.
*A melt freeze cycle is when cold dry snow melts in the sun/heat during the day and then freezes at night. 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. It then becomes progressively softer as the warm sun and increased temperatures melt it as the day goes on. 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 more on how to ski smooth nice spring snow see my article here ‘Spring Skiing Tips – Ski the Smooth’,
Avalanche Bulletin
For most areas in the N French Alps the current avalanche danger level is around a ‘limited’ 2 out of 5. The high more N’ish facing slopes are the ones where the most avalanche instability currently is. If it rains or snows significantly, as it may on Monday, this will probably rise to a 3 out of 5 with instability of wet snow avalanches coming down. It will then probably revert to a 2 out of 5 again later in the week.
Here’s a link to the European Avalanche Warning Services website where you can see the danger level and get the avalanche forecast wherever you are in Europe. It’s a great source of information.
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 with the vast majority on N’ish facing slopes (in the Northern Hemisphere) during December, January and February… a significant minority in March!
Weather forecast : Mon 11th to Fri 15th March thanks to Météo Alpes
A very spring-like feel in the mountains this week. Following a showery day on Monday, the rest of the week will be sunny and feeling mild for the time of season.
MON 18th: A showery day. Rain/snow limit 2200/2300 m. It will clear up towards the end of the day. Fresh snow depths above 2400 m could amount to anything between 10 to 30 cm (combined with snow that fell on Sunday night).
TUES 19th: A return to dry sunny weather with just some thin high altitude cloud. 0°C at 3000 m. Light to moderate N wind.
WED 20th: A sunny spring-like day, with some very thin high altitude cloud.
THURS 21st: Another sunny day in the mountains, with a few cumulus clouds in the afternoon.
FRI 22nd: Feeling very springlike and mild with plenty of sunshine.
NEXT FEW DAYS: Possibly change in the weather – time will tell.
6 day forecast for Courchevel c/o 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 18th March 2024 appeared first on Henry's Avalanche Talk.