Avalanche forecast

Intermountain

Valdez Avalanche Center
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Avalanche danger

Alpine
3 · Considerable
Treeline
3 · Considerable
Below
2 · Moderate
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Out of date — this forecast expired last year. You’re viewing past conditions, not the current bulletin.

Highlights

The avalanche hazard is Considerable above 1500'.  Two plus feet of new snow that fell since the 16th is sitting on a layer of weak snow.  Human triggered avalanches are likely with the depth dependant upon new snow amounts.  Natural avalanches are possible

Avalanche Forecasts are issued Wednesday-Sunday at 8am.  

Avalanche problems

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–2.5

    Dangerous avalanche conditions exist in all three snow climate zones.  18-30 inches of new snow since the 16th has been observed that overlies buried surface hoar in many areas.  This new snow changed during the day yesterday from relatively dry and uncohesive in the morning to heavier and slabby in the afternoon once the sun came out.  This change in the storm snow gives the new snow the energy to produce avalanches that could propagate, and the 3/16 buried surface hoar below could act as a weak layer to initiate failure.

    Observations from yesterday showed that southerly aspects are especially touchy with a small natural or possible remote trigger on Loveland, multiple larger naturals reported by heli ops in the Keystone Glacier area, and numerous naturals on Mile High at mid and upper elevations.   Southerly aspects have all three ingredients necessary to produce an avalanche: Slab(new snow), weak layer(buried surface hoar), and a bed surface ( old melt freeze crust.

    Southerly aspects are not going to be the only problem area though, this buried weak layer is widespread.  Southerly likely reacted first since it was the aspect that gained cohesion the quickest with solar input.  The photo listed here shared by a local supporter shows that shaded aspects harbor instabilities as well.  

    Conservative terrain choices are recommended.  Slab depths are in the range that can readily be triggered by a person or machine and are deep enough to produce avalanches that are large enough to injure, bury, or kill a person.  The current setup could remain sensitive to human triggers for an extended period, more observations are needed and patience is advised.  

    Tracks are not a sign of stability.  Avalanches can be triggered even after numerous tracks have been laid down on a slope. 

    (3/19/2025)

     Natural avalanche in the books that likely failed on 3/16 BSH

    Photo: Eagan Gleasson

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–2

    Wet loose activity will be active today if the sun is able to break through the clouds.  Southerly aspects will be the most affected by this problem today.   Wet loose activity is a secondary concern to problem 1 listed above.  Steep terrain that produces wet loose activity will also have the potential for slab avalanches to fail naturally or be human triggered.   Avoid steep terrain that is being heated up by the sun.  Even small slopes can be dangerous if they are above terrain traps or exposure.  

    Expect southerly aspects to be active in the coming days when the sun is out as new snow sheds from sunny slopes in the form of slab avalanches and wet loose activity.

Avalanche Discussion

Observed Avalanche Activity last 72 hours: 

Numerous D1-D2 Natural and Human triggered avalanches reported from all forecast zones yesterday.

Forecast Discussion:

New snow since 3/16 has now settled into a cohesive slab creating a persistent slab avalanche problem. Human triggered avalanches are likely today 1-3 feet in depth. Snowfall totals are highest near the coast, with 2-3 feet reported and less so on Thompson Pass with near 2 feet @ 5000' observed on 3/19.  The Continental zone had much lower snow totals between 4-12 inches, but numerous natural and human triggered avalanches were reported in that zone as well.

This setup is not only dangerous but can be difficult to assess.  The first person to ski a slope is not necessarily the one that will trigger an avalanche, a slope can fail after numerous tracks have been laid down.  Digging snowpits is a good tool, but can give misleading results as buried surface hoar can be easily missed depending upon where you dig.  In addition, ECTN results are not necessarily an indication that the slope is safe.   Conservative terrain choices and cautious route finding are recommended.  Only expose one person to a slope at a time, know your safe zones maintain good communication with your group, and watch out for other groups that may be recreating in the same area.

Additional Information:

Watch out for cornices. A couple of cornice falls have been observed in the Continental region.

A weather and snowpack season history is available by clicking on the Season Summary tab which is located below the bottom line statement once you have entered the full forecast.

Season Snowfall Data

Location 24 hour Snowfall Inches- 3/20 24 hour Snow Water Equivalent Inches Height of Snow March Snowfall Inches Season Total Snowfall Valdez    0    0    58     18 N/O     Thompson Pass    0    0   N/O     ~24    ~500 Nicks    0    0    146    15 N/O 46 Mile    0     0   22    5 N/O

Regions covered