Avalanche Forecast
Regions: Mt Hood.
Mt Hood should get more snow that the Washington Cascades on Thursday. You may find dangerous avalanche conditions in the alpine.
Detailed Forecast
Mt Hood Forecast
An occluded front should move south to north over the Northwest Wednesday night and Thursday. South to southeast alpine winds Thursday morning should generally shift to southwest Thursday by afternoon.At Mt Hood look for moderate to heavy amounts of snow by later Thursday.
Watch likely new wind slab on lee slopes and new storm slab in calmer less exposed areas. Remember that the avalanche danger will be greater if you encounter stronger winds and heavier snowfall. Evaluate snow and terrain carefully Thursday. Change your plans if you find yourself in unexpectedly prolonged stormy weather.
Less snow below tree line should limit the avalanche danger there.
Snowpack Discussion
Mt Hood Weather:
Snowfall at Mt Hood the first 7 days of December was about 1.5-2 feet with an overall warming trend. Then an atmospheric river arrived the past couple days (Main Fork of the Pineapple Express) and heavy rain with about 5-7 inches at NWAC stations in just 2 days ending this morning. Wow!
But snowfall has resumed on Wednesday with a cooling trend. Good news!
Mt Hood Snowpack and Reports:
The Mt Hood Pro Patrol on Wednesday reports a greatly consolidated and stabilized snowpack. Small new wind and soft slab was beginning to form on Wednesday afternoon.
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: 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: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1 - 1