Size 2 avalanche, North Bowl south end of Hector S Ridge

Date/heure de l'avalanche

jeudi 7 janvier 2021 à 14 h 00

Nombre d'avalanches dans ce rapport

1

Taille de l’avalanche

2

Épaisseur de la plaque

50cm

Largeur de la plaque

150m

Longueur d'écoulement de l'avalanche

200m

Caractère de l'avalanche

• Plaque de neige de tempête

Type d'élément déclencheur

Skieur

Sous-type d'élément déclencheur

Accidentel

Distance du déclenchement à distance

20m

Versant de la zone de départ

• NE

Bande d'altitude de la zone de départ

• Alpin

Exposition au vent

Pente sous le vent

Couverture forestière

Pente dégagée

4 of us were skiing on the south end of Hector S Ridge (“Hector Point”). We noticed no signs of instability on our way up. No signs of natural avalanches were seen.

We evaluated the snow below the cornice (we dug 3 pits a few meters down the slope, all essentially showing sluffing of storm snow CTM and deep planar sheer CTH). We also broke pieces of the cornice to see if they would trigger anything as they tumbled. No reaction.

2 skiers went down with now issues, settlements or cracks. There were no wind slabs on the slope. They stopped low enough to avoid the toe of the debris.

The third skier triggered the slide remotely, approx. 20m below him. Luckily he had a radio and his spotter told him in time to stop him from reaching the crown. He then skied down to the slide path and immediately crossed skiers left on the slide surface to lower angle snow slopes.

Luckily, no one was hurt, swept, or buried.

While the skier did no hang around to do an analysis of the layer that propagated, the crown was 50-60 cm deep, which did not shown anything in the pits. We thus conclude this is wind-transported storm snow that accumulated well beyond the 25cm s’en in the pit, and “sluffed”.