menu

Olympics

Issued: 9:08 PM PST Saturday, March 3, 2018
by Robert Hahn

Despite the continued slow stabilizing trend, specific terrain still has the potential to produce large and destructive avalanches. You can trigger Wind Slabs near and above treeline on leeward slopes. These could result in dangerous Persistent Slab avalanches that are difficult to manage and can break widely. Avoid wind loaded areas and large open slopes 35 degrees and steeper. 

Danger Scalei
  • No Rating (Info Avail)
  • Low (1)
  • Moderate (2)
  • Considerable (3)
  • High (4)
  • Extreme (5)

Avalanche Problems for Sunday

Wind Slabi

  • Avalanche Problemi
  • Aspect/Elevationi
  • Likelihoodi
  • Sizei
 

Persistent Slabi

  • Avalanche Problemi
  • Aspect/Elevationi
  • Likelihoodi
  • Sizei
 

Forecast for Sunday:

You may be able to trigger Wind Slab avalanches at upper elevations where drifted wind features exist. Avoid these avalanches by staying off of recent snow drifts, deeply pillowed features, and fresh cornices on leeward slopes 35 degrees and steeper. Soft non-wind-effected snow may cover wind slabs making them harder to identify. If you trigger an avalanche in the upper snowpack, it could step down and become a dangerously large Persistent Slab avalanche.

You may be able to trigger Persistent Slab avalanches on slopes 35 degrees and steeper. Avoid steep, open slopes and large avalanche paths to reduce your risk of these difficult to manage avalanches. Weak sugar-like facets or buried surface hoar can be found just above a firm crust layer formed in early February on all but south aspects. This layer is down about 2-4 feet. 

Avalanche Summary:

Up to 2 feet of snow fell near Hurricane Ridge in the past week. Winds as recent as Thursday formed Wind Slabs on a variety of aspects near and above treeline. In sheltered areas generally soft unconsolidated surface snow exists. Large snowdepth differences exist between shallow southerly and deeper northerly aspects. 

Some observations suggest other persistent grains may exist at the interface of this week's snow. Facet crust combinations, buried surface hoar, and large preserved stellars have been reported in recent avalanches and snowpack tests at this interface from the West Slopes of the Cascades.

About 3 ft of of settled snow sits on top of the weak persistent grains (see new observation below) that formed on a strong crust earlier in February. Snowpack tests continue to suggest that this interface can fail and produce avalanches. This layer has not been reported on South aspects in the Hurricane Ridge area.

There are no other significant layers of concern in the mid and lower snowpack.

Observations

On Saturday March 3rd, NPS rangers found 2-3mm buried surface hoar from mid February intact on a NNW aspect at 4990’. The surface hoar was about 4" (10 cm) above a crust 32" (80 cm) below the surface. No new or recent avalanche activity was observed on this layer. 

On Friday, March 2nd, NPS rangers reported a large avalanche on a recently wind loaded slope. Elsewhere, profiles showed a faceted weak layer buried in mid- February was found 2-4 feet below the surface and was showing some signs of rounding.

 

No Corresponding Mountain Weather Forecast Available
This information is provided by the U.S.D.A. Forest Service and describes general backcountry avalanche hazard and conditions. It does not apply to ski areas and highways where avalanche mitigation is conducted. Read more here.