CAIC

CAIC: Colorado Avalanche Information Center

BC Zone Observation Report

Monday, January 7, 2013 at 12:00 AM
Vail & Summit County

Details

Date: 2013/01/07

Observer: Scott Toepfer
Organization: Forecaster, CAIC

Location

BC Zone: Vail & Summit County
Area Description: East side of I-70

Weather

Ridgeline Wind Speed: 5-10 mph
Ridgeline Wind Direction: W
Wind Loading: Previous
Sky Cover: Few
Depth of Total Snow: 36 in
Weather Description: Warm & mild day.

Snowpack

Snowpack Description: West aspects pretty much facets top to bottom in a 52 cm deep pack. South aspects recent sun crust development on top of facets. Northeast aspects 95 cm with a mid pack soft slab resting on well developed (3-5mm) depth hoar. Near surface facets for the top 30 cm, mid pack around 25 cm soft slab decaying, Bottom third of pack well developed depth hoar

Snowpack Obsvervation #1

Cracking: None
Collapsing: None
Persistent Weak Layer: Yes
Comments: Pretty much a facet dominate snowpack. Easily capable of loose snow sluffs, little slab present Above treeline sparse snowpack.

Snowpack Obsvervation #2

Cracking: None
Collapsing: None
Comments: Around a meter deep snowpack. Not reactive with ECT test, but propagation saw test was "Whoa". Block "Popped" off basal depth hoar after cutting upslope around 10 cm.

Avalanches

Date

Location/Path

#

Elev

Asp

Type

Trig

SizeR

SizeD

View

2013/01/06 ^†

Vail Pass

1

TL

NE

L

AS

R1

D1

View

2013/01/07 ^†

Vail Pass

1

TL

W

L

AS / u

R1

D1

Media

Images

<b>Figure 1:</b> ECT no result west aspect. Snow depth 52 cm. Pretty much facets top to bottom. 20 degree slope angle (<a href=javascript:void(0); onClick=win=window.open('https://caic-production.imgix.net/6pq2gfa71kaqcbjbfvsrpg2abthr?ixlib=php-3.1.0&s=73c1dae4cbd05dae84d14f4343efbccd','caic_media','resizable=1,height=820,width=840,scrollbars=yes');win.focus();return false;>see full sized image</a>)

<b>Figure 2:</b> Skier triggered sluff on a west aspect. Slope angle estimated at 35 degrees. (<a href=javascript:void(0); onClick=win=window.open('https://caic-production.imgix.net/jiy9dc83nho6wl7aepxxu74hfimg?ixlib=php-3.1.0&s=95b0d3ef3220783f0a87537ecaf93d05','caic_media','resizable=1,height=820,width=840,scrollbars=yes');win.focus();return false;>see full sized image</a>)

<b>Figure 3:</b> ECTN25 NE aspect. Hs = 95 cm. (<a href=javascript:void(0); onClick=win=window.open('https://caic-production.imgix.net/c9gnga9e939hlykx47pzn8fpudzg?ixlib=php-3.1.0&s=86e60c6a3110e937c2823af27da224e7','caic_media','resizable=1,height=820,width=840,scrollbars=yes');win.focus();return false;>see full sized image</a>)

<b>Figure 4:</b> Propagation Saw Test NE aspect. PST10End6012-10 Failed after the first 10 cm, failed to end of column with an audible 'Pop'. Depth hoar weak layer was about 60 cm deep. Block jumped off the depth hoar. A certain 'Whoa" moment. (<a href=javascript:void(0); onClick=win=window.open('https://caic-production.imgix.net/qbocm8hoeissdw8k63qv6ztmqytr?ixlib=php-3.1.0&s=700140f3d31a87f669c38b0a48f89987','caic_media','resizable=1,height=820,width=840,scrollbars=yes');win.focus();return false;>see full sized image</a>)