Bollettino valanghe

Southeast Mountains

Crested Butte Avalanche Center
Vedi sulla mappa

Pericolo valanghe

Tue
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
3 · Marcato
Open full map
Non aggiornato — questo bollettino è scaduto 3 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

It's getting hot, hot, hot!  Dangerous avalanche conditions will develop during the day on mid and low-elevation slopes.  You can easily trigger a Loose Wet avalanche that grows to a large size as the snowpack warms.  Some slopes could produce dangerous Wet Slab avalanches (example from Sunday).  Wet avalanche problems are less likely but remain possible above treeline and looming cornices may fail producing large avalanches.  Start your day early and move through terrain before the snowpack loses strength and becomes wet.  Avoid traveling below corniced lined slopes.

Problemi valanghivi

  • Loose Wet

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    1–2

    Wet Loose avalanches are expected to be largest on mid and lower elevations where warm temps and sunshine weaken the upper snowpack.  Conditions will start the day generally safe with freezing overnight temperatures, but will quickly deteriorate from east to south to west slopes throughout the day and may involve some northerly aspects as temperatures rise.  Safe riding conditions exist with just a few inches of soft snow resting above supportive crusts below.  Once crusts break down and the snowpack becomes punchy to boot, then you should head to low-angled terrain or cooler aspects.  

    4/9:  Large Wet Loose avalanches entrained a lot of mass on a southwesterly aspect of Red Ridge.  These avalanches ran naturally Sunday afternoon.

  • Cornices

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1.5–3

    Large, overhanging cornices continue to fall on a daily basis under our current warming trend.   Some are capable of triggering destructive slab avalanches, while others are trundling down slope entraining large amounts of snow with car-sized chunks of cornice debris.  Limit your exposure on slopes with large cornices above, and give them a wide berth if you are traveling along corniced ridgelines.  

    A recent cornice fall in Redwell Basin.  Minimize your exposure to terrain like this.  

  • Wet Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1.5–2.5

    There is a large degree of uncertainty about the timing and distribution of Wet Slab avalanche releases in the coming days.  The avalanche pictured here from Gibson Ridge came a day or two before expectation.  Wet Slabs are hard to predict and forecast.  Slopes that have become very wet and are likely to produce a loose avalanche should be treated as a suspect for a Wet Slab.  Aspects highlighted in the rose above are the best estimation for the most concerning aspects of Wet Slab release.  Until this warming period passes and meltwater moves through the snowpack or colder weather arrives, consider this potentially deadly threat.

    4/9: 4/9:  A large Wet Slab avalanche ran naturally on the east-facing side of Gibson Ridge.

Avalanche Discussion

The snowpack is finally seeing the first major warm-up of the year.  Expect a dramatic increase in wet snow avalanche hazards for the next few days.  The danger will be safer early in the morning while crusts are frozen, but as soon as the sun begins warming the snowpack the hazard will steadily rise throughout the day.  Anticipate dangerous avalanche conditions to develop over the course of the day.

The primary hazard is Wet Loose avalanches.  A few inches of wet snow above supportive crusts is ideal for riding conditions, but as crust breakdown during the day, Wet Loose avalanches may be able to gouge into the snowpack and entrain enough mass to bury, injure, and kill you.  Large-size avalanches are most likely to occur at lower elevations but may spread to upper elevations in some places on sunny aspects.  The dusty brown snow surface will heat up much faster than a clean, white snowpack so plan to get out early to avoid deteriorating conditions.

Greater uncertainty surrounds Wet Slabs.  These hard-to-predict and potentially destructive avalanches occur when large amounts of meltwater destabilize weak layers deeper in the snowpack.  Again, dusty snow surfaces and rocky areas can help increase the amount of meltwater entering the snowpack and increase the likelihood of Wet Slab avalanches.  Your best defense is to avoid slopes that have become wet enough for Wet Loose avalanches as these are very common on the same slopes as Wet Slabs.  If it is wet enough to produce a loose avalanche then consider that slope a threat for a Wet Slab and head for cooler terrain or lower angled slopes.  Wet Slab concerns will pass once cooler weather arrives in a few days.

Finally, warming temperatures will likely increase the number of cornice falls.  Each day observers note a few more cornice falls and subsequent avalanches.  Simply avoid traveling beneath corniced terrain and give a lot of space while traveling above.  You can't predict which cornice will fail so simply avoid being in harm's way during this warming period.

* In response to the warning trend, the CBAC will issue avalanche forecasts around 730 pm the night before.  Expect to see Tuesday's avalanche forecast Monday night around 730pm. This allows backcountry travelers the ability to plan the night before and not need to wait until forecasts are issued in the morning.*

Regioni coperte