Large Avalanches Scarp Ridge/Irwin Cat Tenure

CB Avalanche Center 2019-20 Observations

Location: Kebler Pass Area
Date of Observation: 02/14/2020
Name: Irwin Snow Safety
Subject: Large Avalanches Scarp Ridge/Irwin Cat Tenure
Aspect: South West, West
Elevation: 10-12,000ft

Avalanches:

Tried a lighter touch and made a huge mess anyhow,

Everything from Spool through the Eyes of the World (SW ATL) is basically gone with 120 to 140 cm crowns running on basal facets on the ground. Complex events with moving slabs triggering additional action. Dramatic. PM form event descriptions are summarized
.

1st event went with a 6lb AB. 2nd event was a single 2×16 and released remotely 10m below the shot. 3rd event triggered by us unloading a 4 shot spread just trying to get the hell out of there. 4th event was a 6lb surface shot cleaning up the remaining hangfire.

All were very large relative to me, but not surpassing D2.5 in size. This area has received intermittent explosive control through the season, but almost no skier compaction. These were the first significant avalanches of the season in all paths that ran.

Spool HS-AB(6lb)-R2/D2.5-G 120cm x 10m x 200m; Right Eyebrow HS-AEr(3lb from 10m)-R2/D2.5-G 140cm x 30m x 200m; Cheddar Bunny Left HS-AE(3lb)-R2/D2-G 140cm x 10m x 200m Left Eyeball Hangfire HS-AE(6lb)-R2/D2-G 140cm x 20m x 150m


Weather: Clear, 20-35 deg, WSW 15-20 g25-46

Snowpack: Good skiing, no signs of instability besides the large explosive triggered avalanches.