Lawinenlagebericht

Gunnison

Crested Butte Avalanche Center
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Lawinengefahr

Sun
Hochgebirge
1 · Gering
Waldgrenze
1 · Gering
Unterhalb
1 · Gering
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Veraltet — dieser Lagebericht ist 6 years ago abgelaufen. Du siehst vergangene Verhältnisse, nicht den aktuellen Bericht.

Kernpunkte

Avalanche conditions are generally safe. However, as more terrain gets skied up, stay aware that you may be forced into the most suspect or higher consequence terrain on your search for fresh tracks. Potental suspect slopes would be northerly facing and included characteristics such as, extreme terrain, a steep and/or unsupported slope, or a recently wind-loaded slope. Yesterday, a skier on Snodgrass mountain triggered a small slab avalanche as they ski cut through a steep start zone. 

Lawinenprobleme

  • Persistent Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Unlikely
    Größe
    1

    A patchy distribution of wind drifted slabs on top of old, sugary snow exists on some high elevation, northerly-facing terrain features.  Although these persistent slabs are difficult to trigger and relatively small, they can cause trouble if they drag you over rocks, stumps, or early season obstacles.  Be cautious of terrain where you find thick, dense snow overlying a continuous layer of weak, faceted snow on the ground.

    High northerly aspect? ☑. Smooth ground cover? ☑. Weak snow on the ground? ☑. Windloaded slab? ☑. Here's what it looks like when you've found the ingredients for our current persistent slab problem.

Avalanche Discussion

Clear sky, and cold overnight temperatures, are combining to eat "Slabs" like Thanksgiving Turkey round two. As slabs facet away, we'll have facet sluffs on the horizon for mid and low-elevation northerly facing slopes. However this transition is a process, we are not there yet, and we can't completely rule out the isolated human triggered slab avalanche. Yesterdays human triggered avalanche on Snodgrass was the only slab avalanche reported below treeline this season, and only the 2nd Persistent Slab Avalanche releasing near the ground since the Persistent Slab Avalanche Problem was added to the problem list in early November. 

Above treeline on northerly facing slopes you can also find weak October snow near the ground, and in some areas a slab above, creating the Persistent Slab Avalanche Problem. The only recorded avalanche releasing near the ground on October snow was recorded November 8th during the first loading period for this weak layer. On November 14th, we had an extreme wind event, with NW winds gusting into the 90's at 12,000ft. That wind blew right up many northerly facing slopes, creating windboard and hard slabs. Those hard layers of snow will make it even more difficult for the weight of a human to affect the weaker snow below. We may need to find a trigger point to release one of these avalanches. Such as where the snowpack thins near rock outcrops or the slabs margins, or maybe a slope that was protected from that extreme wind event. 

Human triggering a slab avalanche is unlikely. However, you must remember, even a small avalanche this time of year could have a high consequence as it drags you through early season hazards, such as exposed rocks, stumps, and trees. Consider the consequence of an avalanche in the terrain you are riding. As more and more terrain gets skied up, you may find yourself being pushed into more suspect or higher consequence terrain, on the search for fresh snow. 

Mark your calendars! December 4th is CBAC's Virtual Avalanche Awareness Night.  A party and educational event, the likes of which you've never seen before.

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