Avalanche Forecast
Regions: Mt Hood.
New and previous wind slab found mainly on northwest to southeast slopes above treeline continues to be the most likely avalanche problem on Mt. Hood. Any new snow that does fall through Tuesday afternoon will likely be transported to lee easterly slopes near and above treeline.
Detailed Forecast
Only light new snow accumulations are expected through Tuesday afternoon and skies should remain mostly cloudy at Mt. Hood with moderate to occasionally strong west winds above treeline. A cooling trend that begins late Monday night will continue during the day Tuesday.Â
Wind slab formed over the weekend and found mainly on northwest to southeast slopes above treeline continues to be the most likely avalanche problem on Mt. Hood. Watch for firmer wind transported snow mainly on these aspects. Any new snow that does fall through Tuesday afternoon will likely be transported to lee easterly slopes near and above treeline.Â
Snowpack Discussion
Weather and Snowpack
An atmospheric river arrived Tuesday 1/17 with rain up to about 7000 feet on Mt. Hood. From Thursday 1/19 through Sunday 1/22, generally 15-20 inches of snow accumulated at NWAC Mt Hood stations.
A large upper ridge and warm air mass built over the Northwest Thursday to Saturday. By Saturday temperatures had reached the 40's with light winds at the NWAC Mt Hood stations.
A front crossed the Northwest Sunday afternoon causing moderate southwest winds, slight cooling and no measurable precipitation.
Recent Observations
NWAC pro-observer Laura Green was at Mt Hood Meadows Thursday and Friday and reported dripping trees and roller balls due to loose wet snow on solar slopes. She reported a general lack of weak layers with ice layers in the snow pack on most aspects but good skiing still to be found on some slopes depending on aspect, elevation and timing.
A worthwhile conditions report for the Reid Glacier for Friday is also available via the NWAC Observations page.
The Mt. Hood Meadows pro-patrol reported little in the way of avalanche activity over the last few days but did note a thin melt-freeze crust up to 6600 feet Monday morning along with some wind transport of previous snow that had occurred above 6500 feet Sunday.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.
Likelihood: Possible
Expected Size: 1 - 1