Gunnison

Avalanche

Ian Havlick · Jan 11, 2014 · Gunnison

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Weather

SCT clouds, moderate SW winds with intense transport above treeline. On slope slide was triggered, previous wind loading evident, but minor loading when on route in this area. Weather: Clear and cold (low 12º) morning, warmed up quickly to a high of 30º. SW Winds remained strong throughout day averaging mid 20s, and Gusts to 56mph. intense solar. High cirrus and altostratus began streaming in from the West around 1530.

Snowpack

Snowpack: Theme of day was intense wind transport at ridgetop. PWL were interesting. Basal facets near ground remained unreactive, as did new windslabs on both East and West terrain. Only minor pockets and cornices would fail under ski cuts and stomping and generally unreactive to aggressive explosive work. 3 large collapses by guided group. Snow surfaces began to get moist around noon, with numerous rollerballs and rollerballs that would grow large before breaking apart as it rolled downslope. Settlement 3”. 72” to 69”. HOWEVER….single 2# handshot in a 36º, East facing coulior, few feet off of rock (shallow,weak point), pulled out an impressive slide (SS-AE-R3-D2.5-O) that propagated across funnel-entry, ran through cliffband, then propagated skier’s right 1500ft. Crown depth ranged from 8-150cm deep, and left debris up to 350cm deep. Slab was Fist to 1F hardness. Weak layer was 2-3mm buried near surface facets above the Dec. 31st MFcr. 3 explosive shots in 35º, South-facing terrain did not produce a slide, but did produce significant cracking and sensible “drop” underfoot in the snowpack. Investigation revealed deeeep cracking, over a meter deep. Snowpack: Theme of day was intense wind transport at ridgetop. PWL were interesting. Basal facets near ground remained unreactive, as did new windslabs on both East and West terrain. Only minor pockets and cornices would fail under ski cuts and stomping and generally unreactive to aggressive explosive work. 3 large collapses by guided group. Snow surfaces began to get moist around noon, with numerous rollerballs and rollerballs that would grow large before breaking apart as it rolled downslope. Settlement 3”. 72” to 69”. HOWEVER….single 2# handshot in a 36º, East facing coulior, few feet off of rock (shallow,weak point), pulled out an impressive slide (SS-AE-R3-D2.5-O) that propagated across funnel-entry, ran through cliffband, then propagated skier’s right 1500ft. Crown depth ranged from 8-150cm deep, and left debris up to 350cm deep. Slab was Fist to 1F hardness. Weak layer was 2-3mm buried near surface facets above the Dec. 31st MFcr. 3 explosive shots in 35º, South-facing terrain did not produce a slide, but did produce significant cracking and sensible “drop” underfoot in the snowpack. Investigation revealed deeeep cracking, over a meter deep.

Avalanche

many many avlaanches obvious around zone. handful of R3-R4 slides on peaks north of Kebler and West of Kebler. Majority within new-ish snow, but some very large, deep, destructive. Owen, Richmond, South Mineral Point, Red Lady repeat offender, 4 slides onto Kebler pass road, steep BTL meadows and rollovers, and the slide triggered within the Irwin Tenure with very large propagation.