Avalanche Forecast
Regions: Olympics.
Heat related loose wet avalanches and cornice releases will be possible on Thursday. You will need to be able to evaluate avalanche conditions on specific terrain features and change your plans if snow conditions are more dangerous than expected.
Detailed Forecast
Sunny, warm weather is expected on Thursday.
Loose wet avalanches, mainly involving any recent storm snow from Monday and Monday night, will be possible on any steep slope, especially during the warmest part of the day Thursday afternoon. Pay attention to the integrity of surface crusts formed overnight. Backcountry travel early in the day is recommended since conditions can change rapidly due to daytime warming. Watch for wet snow deeper than your boot tops especially on steep solar slopes during the midday and afternoon hours.
The likelihood of cornice releases will continue on Thursday from intense solar radiation and warming temperatures. Cornice releases can be unpredictable during the spring so avoid areas below cornices and remember that cornices can break much further back than expected along ridges.
Any wind slab deposits caused from the snow received Monday, in combination with moderate westerly winds should have mostly stabilized by Thursday and wind slab won't be listed as an avalanche problem on Thursday. However, continue to watch for signs of wind slab mainly on north to east facing slopes above treeline where extra caution is warranted.  Firm wind transported snow and snowpack cracking can be good signs of wind slab layers.
Although not listed as an avalanche problem, large, powerful glide avalanches can release unexpectedly so avoid areas below steep unsupported slopes or rock faces.
Snowpack Discussion
Weather and Snowpack
A large upper ridge dominated the weather last week through early Sunday, resulting in warm and dry weather. A spring avalanche cycle occurred in most areas over this stretch, likely peaking midweek in the Olympic range. After a stormy March, the snowpack has undergone significant settlement and multiple melt-freeze cycles over the last week.
A front moved across the Olympics early Monday morning, resulting in a period of mostly light precipitation, cooling and moderate westerly crest level winds.
Another upper ridge is currently over the Northwest causing sunny weather and warm temperatures.Â
The mid and lower snowpack in the Olympics should generally be a stable mix of crusts and layers of moist and rounded snow crystals.
Recent Observations
During the warm stretch last week, 1 large glide avalanche (R3-D3) naturally released on the 20th of June slide path (easterly aspect, near treeline) to the ground. According to NPS rangers, the avalanche likely released on Wednesday or Thursday.
NWAC pro-observer, Matt Schonwald toured extensively in the Hurricane Ridge area Saturday, 4/2 and found a well settled and seasonally deep snowpack with very few avalanche concerns. Â
Only shallow amounts of recent snow were received Monday through early Tuesday at Hurricane Ridge. This lead to a slight increase in danger, mainly on specific terrain features such as any exposed lee slopes at higher elevations that received greater wind deposited snow.Â
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: All aspects.
Elevations: All elevations.
Likelihood: Possible
Expected Size: 1 - 1
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 lips 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.
Cornices can never be trusted and avoiding them is necessary for safe backcountry travel. Stay well back from ridgeline areas with cornices. They often overhang the ridge edge can be triggered remotely. Avoid areas underneath cornices. Even small Cornice Fall can trigger a larger avalanche and large Cornice Fall can easily crush a human. Periods of significant temperature warm-up are times to be particularly aware.
A corniced ridgeline. A large cornice has formed at the top of the ridge. A smaller cornice has formed to the left of the trees from crossloading.
Cornices are easy to identify and are confined to lee and cross-loaded ridges, sub-ridges, and sharp convexities. They are easiest to trigger during periods of rapid growth (new snow and wind), rapid warming, and during rain-on-snow events. Cornices often catch people by surprise when they break farther back onto flatter areas than expected.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1 - 1