Storm Creek Old Large Avalanche

Date/heure de l'avalanche

dimanche 27 décembre 2020 à 08 h 02

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

> 48 heures

Nombre d'avalanches dans ce rapport

1

Taille de l’avalanche

3

Largeur de la plaque

400m

Longueur d'écoulement de l'avalanche

150m

Caractère de l'avalanche

• Plaque profonde et persistante

Type d'élément déclencheur

Naturel

Versant de la zone de départ

• NE

Bande d'altitude de la zone de départ

• Alpin

Altitude de la zone de départ

2 200m

Inclinaison de la zone de départ

35°

Type de cristaux de la couche fragile

• Grains à faces planes

Exposition au vent

Pente chargée latéralement

Sometime during the pre-Christmas storm IT looks like the slope below Storm Creek Headwall from below Kaveology to Smith & Wesson went naturally.

I estimate it was about 400m wide. It ran about 150-200m to the bottom of the valley and a short way into the trees in places. Crown was filling in so can’t say how deep but based on the crusade crossloaded and spindrifted nature of the slope and depth of the snowpack I would guess it probably varied from 1-2m.

I presume it failed on facets deep in the snowpack in order to have such a wide propagation. Presumably the early Nov crust could be implicated though I didn’t find much evidence of that crust on earlier forays to this location.

Likely triggered by avalanche falling from above the headwall.

Of note is that the large couloir right of the headwall also ran 3/4 path but did not pull a slab down low.