Dashboard Regions Weather Stations Radar Alerts Glossary
Contact About
Log In

Register for an account and never miss a forecast again!

Register

Avalanche Forecast

Archived

Mar 9th, 2014–Mar 10th, 2014

Alpine
Natural avalanches unlikely, human triggered possible.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely, human triggered possible.
Alpine
Natural avalanches unlikely, human triggered possible.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely, human triggered possible.

Regions

Olympics.

Less avalanche danger is expected on Monday.

Detailed Forecast

Light rain or snow showers should be seen on on Monday and end Monday night at slightly lower snow levels. But amounts should be light in the Olympics and not cause a significant or extensive new avalanche danger.

Further consolidation and stabilizing should be the main trend and the avalanche danger will be lower on Monday than the past few days.

The equinox is not too far off and the sun is gaining power. Further triggered wet loose avalanches will be possible on Monday mainly below treeline. Watch for pinwheels and surface wet snow deeper than a few inches.

There were cornice failures the past few days at Hurricane and further natural or triggered cornice failures should be possible at Hurricane. Avoid walking on or below cornices.

Old small areas of wind slab might still be seen at the highest elevations. Watch for signs of firmer wind transported snow in the highest areas above treeline.

Snowpack Discussion

The past month has had 2 major storm cycles and periods of avalanches in the Olympics and Cascades.

The first two week storm cycle ended about 25 February that produced about 9 feet at Hurricane and avalanches at Hurricane and across region.

NWAC observers Tyler and Katie Reid on Friday reported wet and saturated upper snow pack layers but with no positive snow pit test results and numerous wet loose avalanches to size 2. Warming effects had penetrated quite deeply into upper snowpack layers.

Here is a video from Tyler and Katy at Hurricane on Friday.

The second storm cycle is coming to an end on Sunday morning. This storm cycle turned out to be basically as wet as the last one! Water equivalents and snowfall for the past week are about 4 inches and 2 feet for Hurricane Ridge. So this has been another period of rain and wet heavy snowfall. This produced many avalanches the past week including reports from Holden Village, Stevens Pass, Tumwater Canyon, Alpental and Snoqualmie with pass closures at times last week.

Reports from the ranger and also Tyler and Katie on Sunday indicate quite a few recent cornice failures on Saturday.

Problems

Loose Wet

Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.

Cornices

Cornice Fall is the release of an overhanging mass of snow that forms as the wind moves snow over a sharp terrain feature, such as a ridge, and deposits snow on the downwind (leeward) side. Cornices range in size from small wind drifts of soft snow to large overhangs of hard snow that are 30 feet (10 meters) or taller. They can break off the terrain suddenly and pull back onto the ridge top and catch people by surprise even on the flat ground above the slope. Even small cornices can have enough mass to be destructive and deadly. Cornice Fall can entrain loose surface snow or trigger slab avalanches.

Wind Slabs

Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.