Avalanche Forecast
Regions: Olympics.
The overall snowpack is strong and well consolidated after more than a week of mild, dry weather. Watch for shallow wet surface snow conditions on some steep sun exposed slopes, especially below rocks or cliffs and above terrain traps where even small slides could be dangerous.
Detailed Forecast
More of the same conditions are expected Monday. Mostly sunny and warm with light winds.Â
In the Hurricane Ridge area, temperatures have reached the mid-50's Sunday with similar conditions expected Monday.
Surface melt-freeze crusts are forming overnight on some solar exposed slopes and softening through the day. Loose wet avalanches are unlikely, but might be encountered in isolated steep solar exposed slopes below rocks or trees absorbing more radiation. Â
The nice riding and skiing conditions found Sunday should remain on Monday as little change in the snowpack structure is expected.Â
Early season terrain hazards still exist, such as poorly covered rocks, vegetation and creeks, particularly at lower elevations, and on exposed ridges where wind events have stripped much of the seasons snowcover.
Snowpack Discussion
High pressure has now been over the region for a full week. Sunshine and very mild temperatures have been the story with cooler temperatures at lower elevations.
This weather has allowed for some small loose wet slides on steep solar exposed slopes, mainly isolated to the terrain below the rocks gaining additional heat. The snowpack consists mainly of surface melt freeze crusts forming overnight on solar aspects and on shaded aspects, settled and well consolidated older snow, still providing some nice skiing and riding conditions.
Stronger winds earlier in the weak may have built areas of small wind slabs but these have mostly settled and bonded.Â
The total snowpack height in the Hurricane Ridge area consistently varies from about 3-4 feet in most areas and aspects. Many wind exposed ridges have been stripped of snow, however, just below ridges, the consistent depths of 3-4 feet are present.
The snowpack is well consolidated and strong with settled old storm snow of about 1-1.5 feet over the strong Thanksgiving rain crust. Snow below the crust is also strong.
The snowpack in the Hurricane area is showing no signs of weaknesses and providing some excellent ski and riding conditions.
During this high pressure pattern, surface hoar may be growing in the sun and wind sheltered terrain. We need to watch for surface snow conditions as they may have an impact on future avalanche conditions when snowfall returns.Â
Observations
NWAC Professional Observer Matt Schonwald was in the Hurricane Ridge area on Sunday, December 10. The average height of snow in most areas was consistently around 4 feet deep. About 16 inches of settled and creamy snow was found well bonded to the Thanksgiving rain crust with strong snow to the ground.
Terrain up to 45 degrees was skied with no signs of instability. Only a few isolated loose wet slides were evident from the past day or so and were small and isolated to steep slopes above terrain absorbing greater radiation, such as cliff and rock band features.
There was some small surface hoar growth on sheltered E-SE facing slopes, not receiving direct low angled sun. No surface hoar or near surface faceting was seen on other slopes, including north facing.
The Hurricane rangers on Friday and Saturday reported few small pinwheels on solar road cuts from the past couple days, no avalanches, with settled powder lingering on north and east slopes.
Avalanche Problems
Loose Wet
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. They generally move slowly, but can contain enough mass to cause significant damage to trees, cars or buildings. 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.
Travel when the snow surface is colder and stronger. Plan your trips to avoid crossing on or under very steep slopes in the afternoon. Move to colder, shadier slopes once the snow surface turns slushly. Avoid steep, sunlit slopes above terrain traps, cliffs areas and long sustained steep pitches.
Several loose wet avalanches, and lots of pinwheels and roller balls.
Loose wet avalanches occur where water is running through the snowpack, and release at or below the trigger point. Avoid terrain traps such as cliffs, gullies, or tree wells. Exit avalanche terrain when you see pinwheels, roller balls, a slushy surface, or during rain-on-snow events.
Aspects: South East, South, South West.
Elevations: All elevations.
Likelihood: Unlikely
Expected Size: 1 - 1