CAIC

Details

Date: 2013/02/02

Observer: markus beck

CAIC Comments

I have added two more fotos from another observer to this observation. It is believed that this run was called "Rush Chute" at the old Berthoud Pass ski area.

Location

BC Zone: Front Range
Area Description: Berthoud Pass W side

Weather

Ridgeline Wind Speed: 5-10 mph
Ridgeline Wind Direction: NW
Wind Loading: Light
Sky Cover: Few
Depth of New Snow: 4 in
Weather Description: Blue Bird day with several inches of freshies on the ground. Winds calmed down the previous night so the new snow was little wind affected. Day temps warmed to near below freezing levels (est. 24F). This is a classic situation where a weak snowpack is being tested by powder starved minds.

Snowpack

Snowpack Description: LOTS OF ACTION ON BERTHOUD PASS TODAY! 2 human triggered avalanches with one person caught but not buried and uninjured. Several recent avalanches observed in and near the area. Some collapsing and shooting cracks observed while skinning. Overall weak snowpack structure being stressed by recent storm and wind loaded snow. Touchy conditions, small to moderate avalanches are likely to be human triggered. We traveled E-N aspects around treeline. Snowpack is made up of large basal facets (F), old df wind slab (P, 1F/4F, new storm slab (F). CT consistently scored VE to M (on isolation to 12 taps), Q1. It seems that if the old windslab is 4F/1F to P and 20cm-60cm thick, slab fracture and propagation is most pronounced. I am rating stability around treeline on N-E as poor.

Avalanches

Date

Location/Path

Elev

Asp

Type

Trig

SizeR

SizeD

2013/02/02

Berthoud Pass west side

Media

Images

<b>Figure 1:</b> View from the road at Berthoud Pass. SS-AR-R2D2-G(dh) above cliffs. The snowboarder was lucky getting flushed against some trees instead of going over the cliff. (<a href=javascript:void(0); onClick=win=window.open('https://caic-production.imgix.net/k78stvbxhzkbxzdzp2fjl6ubdox9?ixlib=php-3.1.0&s=b1237ef75fe8dc0fc49362c56f9c99e0','caic_media','resizable=1,height=820,width=840,scrollbars=yes');win.focus();return false;>see full sized image</a>)

<b>Figure 2:</b> Looking down from just above the crown. Some debris piled up against the trees, while most of the avalanche spilled over the cliff. (<a href=javascript:void(0); onClick=win=window.open('https://caic-production.imgix.net/sag9p7c600vg91h6fskvcjfowha9?ixlib=php-3.1.0&s=5fd1e1a7d080b16c28c2b8328f1c8d39','caic_media','resizable=1,height=820,width=840,scrollbars=yes');win.focus();return false;>see full sized image</a>)

<b>Figure 4:</b> On a nearby very similar slope on a NE aspect, a party of skiers produced shooting cracks running about 80ft. They then proceeded to ski a N facing slope (est. at 36dgr) without further incident. NOTE: a snowpit next to that slope showed that same structure, with CT11+12 Q1 failing on large basal dh. (<a href=javascript:void(0); onClick=win=window.open('https://caic-production.imgix.net/my3qzbfydj293s1lofeyv8hwa1l6?ixlib=php-3.1.0&s=b2af020d34fe72f4a62f350cc0d3a974','caic_media','resizable=1,height=820,width=840,scrollbars=yes');win.focus();return false;>see full sized image</a>)

<b>Figure 5:</b> Russel's SE face was triggered by a snowboarder, around noon (est); tracks exiting the slide indicate that the person did not get caught. Members of the Alpine Rescue Team, dispatched to the slide at the Pass, later performed a quick check of the site to insure no one was caught. (<a href=javascript:void(0); onClick=win=window.open('https://caic-production.imgix.net/skz2qrelh6ghienbihmf6nehgm7r?ixlib=php-3.1.0&s=18898632e466a60bad3007fae8752e53','caic_media','resizable=1,height=820,width=840,scrollbars=yes');win.focus();return false;>see full sized image</a>)

<b>Figure 6:</b> A view from below the avalanche. Search and rescue team members are along the ridge. A rescuer and the snowboarder who triggered the slide can be seen a little up & to the right of center frame. Photo courtesy Ric Ondrusek Alpine Rescue Team (<a href=javascript:void(0); onClick=win=window.open('https://caic-production.imgix.net/0rfp1ka3fujmp8dv9ku29nfm5hfy?ixlib=php-3.1.0&s=a2c45ac82f16b20159bf40c06710dbac','caic_media','resizable=1,height=820,width=840,scrollbars=yes');win.focus();return false;>see full sized image</a>)

<b>Figure 7:</b> A view of the crown and bed surface
Photo courtesy Ric Ondrusek Alpine Rescue Team (<a href=javascript:void(0); onClick=win=window.open('https://caic-production.imgix.net/msu5szm6z8btl752r2gy9m6mwzhi?ixlib=php-3.1.0&s=57c45a4a938d0deda15f0d594d3156c9','caic_media','resizable=1,height=820,width=840,scrollbars=yes');win.focus();return false;>see full sized image</a>)