Cobra Great

Found less than 15 cm of new snow at the Moraine Lake road parking lot in the morning. Deepest (not windloaded) HN was 20cm near Annette Lake. Observed significant wind transport from the SW above 3000m from first light on Temple. At Lake Annette, we noticed that all north facing paths had avalanched in the last 24 hours with debris reaching 1/2 to 3/4 fan. Cobra Couloir had the largest debris, i.e. SZ 2.5 up to 1m deep covering nearly 3/4 of the whole fan. The crown of the avalanche could be observed at the very top of the couloir. Very little snow was left on cliffs above and on the sides of the Cobra. The couloir proper had an average of 30cm of soft slough debris in it with isolated November 8 crust pockets. Little trickle sloughs came down every 15 minutes or so with the bigger wind gusts on the neighbouring cliffs. No instability was noticed until 20m below the old crown where a 5-10cm thick 1F slab burried 20cm down gave an easy sudden collapse non-planar result on facets. We pulled the plug then and enjoyed great skiing down the couloir and on the loaded east side of the fan. No avalanche activity observed all day.

Size 2.5 had ran the couloir top to bottom (3/4 fan) in the last 24 hours. Similar activity was noticed on most other extreme terrain on the North Face of Temple. No activity other than trickle sloughs were noticed all day even though the winds were blowing strong from the SSW all day above 3000m.

Wind transport could be observed on Temple's north glacier from the first light. Some small sloughs could be observed pouring over cliffs up high and dissipating under wind action before hitting any slope below. Wind remained strong all day above 3000m.

Most of the couloir had sloughed in the last 24 hours or so and no overhead could be seen on the cliffs above and on the sides of the couloir. The crown could be observed from mid fan. There was ongoing reloading of the couloir with trickle sloughs coming down in small isolated runnels when a big wind gust would come every 15 minutes or so. The reloading was mostly F to 4F resistance until reaching 20m below the old crown at the top of the couloir where a 5-10 cm thick slab burried 20cm down gave sudden collapse non-planar results on facets.