Avalanche Forecast
Regions: Mt Hood.
Fresh wind slab found in the near and above treeline bands will create dangerous avalanche conditions and will be the primary avalanche problem on Tuesday. Look for signs of recent wind loading and don't assume a lack of natural avalanche activity means a slope can't be human triggered!
Detailed Forecast
A weak front will approach the area Tuesday spreading high clouds over the area in the afternoon. After a cool start Tuesday morning freezing levels should moderate a bit into the afternoon.Â
Fresh wind slabs in the near and above treeline bands found mainly on lee easterly aspects will be the main avalanche problem Tuesday. Watch for signs of firmer wind transported snow that indicate wind slab. Storm slabs should be more difficult to trigger and isolated on Tuesday since storm snow instabilities have had time to settle.Â
In much of the below treeline band there is not enough snow yet for avalanches.  Avalanche problems should be limited to the upper part of this elevation band.
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Snowpack Discussion
Weather stations on Mt. Hood picked up 11Â and 15 inches at Timberline and Mt. Hood Meadows respectively through early Monday morning with several more inches falling in heavy showers through the daylight hours on Monday. W to NW wind remained moderate on Monday helping to transport new wind to lee easterly aspects.Â
The Mt. Hood Meadows pro-patrol found sensitive but soft 6-12" storm slabs on most aspects Monday morning failing within the new storm snow. Â Wind slabs averaged 18" on north aspects above treeline with a crust for a bed surface that formed during a warm-up last Friday.Â
In general the below tree-line elevation band has plenty of terrain anchors and offers lower avalanche potential due to the shallow snowpack.Â
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, North West.
Elevations: Alpine, Treeline.
Likelihood: Likely
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: All elevations.
Likelihood: Possible
Expected Size: 1 - 1