Widespread Wind Redistribution

Date/heure de l'avalanche

mercredi 10 janvier 2018 à 13 h 00

Estimation de l'heure d’occurrence de l’avalanche

< 12 heures

Nombre d'avalanches dans ce rapport

1

Taille de l’avalanche

1.5

Épaisseur de la plaque

15cm

Largeur de la plaque

25m

Longueur d'écoulement de l'avalanche

100m

Type d'élément déclencheur

Skieur

Sous-type d'élément déclencheur

Accidentel

Altitude de la zone de départ

1 550m

Inclinaison de la zone de départ

32°

Croûte près d'une couche fragile

Non

Exposition au vent

Pente chargée latéralement

Couverture forestière

Pente dégagée

Came across a skier-triggered windslab today. Skier was fine, standing nearby, as was his partner. I did a little digging at the edge of the crown. Interestingly, the Friday rain crust was about 60cm down in this location. The crown was a stiff (crusty on the surface) wind slab that entrained a couple inches of more unconsolidated snow from below. Under that, I was surprised to find a layer of facets and then another more consolidated layer above the crust.

In the attached picture, I've dug out the area down to the crust. You can see the faceted layer underneath the surface slab, and the more consolidated snow underneath.

Skied across most polar aspects today and found a massive redistribution of snow since yesterday. Wind affect was widespread above 1300m and very pronounced above 1500m. Certain slopes were more skiable than others, but still had evidence of wind affect. Many slopes had a hard zipper-crust breakable wind slab on the surface ranging from 0.5-3" thick. We encountered reactive wind slabs up to 30cm in isolated areas that released on a single tap in a hand pit.

We skied some moderately steep terrain but tip toed around through obvious larger wind slabs. There was evidence of wind deposition of snow (since yesterday) as low as 1000m, and in open alpine terrain, the amount of snow on top of the crust ranged from 10cm-60cm.

Busy day up there, hopefully everyone stayed safe!