Avalanche Forecast
Regions: Mt Hood.
Storm and wind slabs remain possible Tuesday, especially on lee aspects near and above treeline. Watch for wind transported new snow received Sunday and Monday, especially higher terrain.
Detailed Forecast
An incoming frontal system will brush the Mt Hood area Tuesday and bring light rain and snow. Snow levels should lower Tuesday to allow for shallow storm and wind slabs, especially on lee aspects near and above treeline.Â
Although new storm and wind slabs are expected to be shallow, expect a greater avalanche danger as one travels higher into the above treeline band Tuesday.  Â
Below treeline, less snow accumulations and weaker winds area expected.Â
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Snowpack Discussion
After last weekend's rain (Jan 24-25th), predominately mild or sunny weather settled in during the work week. This help increase the very strong near surface crust layers.  A frontal system crossed the PNW on Sunday and another on Monday, producing light to moderate amounts of new snow Sunday mainly above 6000 ft with moderate westerly transport winds above treeline. Monday's front was warmer with rain reaching to about 6500 feet or higher.Â
No new avalanches have been reported over the last week or as of Monday evening.Â
Overall the snow pack at Mt Hood should predominately consist of stable consolidated rounded grains or melt form layers and crusts from warm periods so far this winter.
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
Storm Slabs
Release of a soft cohesive layer (a slab) of new snow that breaks within the storm snow or on the old snow surface. Storm-slab problems typically last between a few hours and few days. Storm-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.
You can reduce your risk from Storm Slabs by waiting a day or two after a storm before venturing into steep terrain. Storm slabs are most dangerous on slopes with terrain traps, such as timber, gullies, over cliffs, or terrain features that make it difficult for a rider to escape off the side.
Storm slabs usually stabilize within a few days, and release at or below the trigger point. They exist throughout the terrain, and can be avoided by waiting for the storm snow to stabilize.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1 - 1