Avalanche Forecast
Regions: Mt Hood.
The greatest avalanche problem should be wind slab on lee slopes near and above treeline mainly NW-N-SE facing slopes below ridges. Watch for signs of firmer wind transported snow.
Detailed Forecast
Light winds and with periods of light snow showers with continued cool temperatures should be seen on Sunday at Mt Hood. A skiers delight! But continue to evaluate snow and terrain carefully on Sunday.
This weather should bring a gradually decreasing avalanche danger on Sunday. Storm layers that may exist above the new crust will slowly settle but could remain reactive to human triggers mainly in the above treeline Sunday.Â
The greatest avalanche problem should be wind slab on lee slopes near and above treeline mainly NW-N-SE facing slopes below ridges. Watch for signs of firmer wind transported snow.
Watch for storm slab in areas that had rapidly accumulating snowfall.
Snowpack Discussion
Warm wet weather will have caused increasing wet snow conditions at Mt Hood Wednesday-Thursday.
A strong occluded front with strong winds crossed the Northwest on Friday. NWAC stations at Mt Hood had about a foot of new snow by Saturday morning. Some areas in the Cascades are reporting a strong bond to the new crust and some a poor bond depending on when new snow arrived. However, even where good bonding exists there may be sensitive storm layers within the new snow. These storm layers may make for some sensitive triggered slabs and will take a bit of time to stabilize.
The Mt Hood Meadows pro-patrol today reported mainly 4-8 inch storm slab released by ski cuts in the above tree line.
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