Avalanche Forecast
Regions: Mt Hood.
Take time to identify features where wind loading has occurred and go around them and watch for sun effects on steep solar slopes.
Detailed Forecast
Fair weather should be seen Monday with a warming trend.
Previous mostly small wind slab may linger mainly on lee north to southeast slopes. Watch for signs of firmer, hollow wind transported snow.
Some sun and warmer temperatures should make loose wet avalanches possible on steep solar slopes. Watch for wet surface snow deeper than a few inches on solar slopes and roller balls that usually precede loose wet avalanches.
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Snowpack Discussion
A warm front last Thursday caused heavy rain on the Washington volcanoes with lighter rain at Mt Hood. While an avalanche cycle was seen in the Washington Cascades this mainly caused consolidation at Mt Hood.
This was followed by cooler weather and some snow. NWAC stations at Mt Hood indicate about 6-9 inches for the 2 days ending this morning.
The Mt Hood Meadows pro patrol today near tree line reported isolated 2-6 inch storm slabs released by ski cuts on lee N-NE slopes. A stable surface crust was reported below tree line.
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Avalanche Problems
Wind Slabs
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.
Wind Slabs form in specific areas, and are confined to lee and cross-loaded terrain features. They can be avoided by sticking to sheltered or wind-scoured areas..
Wind Slab avalanche. Winds blew from left to right. The area above the ridge has been scoured, and the snow drifted into a wind slab on the slope below.
Wind slabs can take up to a week to stabilize. They are confined to lee and cross-loaded terrain features and can be avoided by sticking to sheltered or wind scoured areas.
Aspects: North, North East, East, South East.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1 - 1
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: Possible
Expected Size: 1 - 1