Avalanche Forecast
Regions: Mt Hood.
UPDATED - A stronger storm than forecast has created dangerous avalanche conditions. Natural avalanches are likely and human triggered avalanches very likely! Travel in avalanche terrain is not recommended Tuesday.
Detailed Forecast
Continued moderate snow showers Tuesday and strong westerly winds will maintain dangerous avalanche conditions. Widespread unstable snow exists within all avalanche terrain in the Mt Hood area. Natural or triggered avalanches are very likely.Â
Travel in avalanche terrain is not recommended Tuesday.
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Snowpack Discussion
...UPDATED 935 AM TUESDAY... HIGH AVALANCHE DANGER. AN AVALANCHE WARNING HAS BEEN ISSUED FOR THE MT HOOD AREA.Â
Weather and Snowpack
The most recent warm and wet SW storm arrived on Valentines Day 2/14 and formed the uppermost very strong rain crust in our snowpack.Â
About 2 feet of snow accumulated at the NWAC Mt Hood stations from Sunday, 2/19 through Wednesday 2/22.Â
Weak weather systems Sunday and again Monday, deposited about another foot of low density snow by Monday evening with light to moderate westerly transport winds near and above treeline. Â Â
Recent Observations
A widespread loose dry avalanche cycle was observed by the Meadows pro-patrol in steep terrain up to 8000 feet on Saturday.Â
On Sunday, the Meadows pro patrol reported pockets of fresh 12-18" wind slab on NE and E aspects near and above treeline that were easily ski triggered but not running far during avalanche control work.
... updated Tuesday morning 2/28 - Mt Hood pro patrol reported widespread natural and triggered wind and storm slabs Tuesday morning, especially near and above treeline. Avalanches occurring even on relatively low angled terrain. Over 2 feet of new snow has accumulated in the past 24 hours with strong winds near and above treeline, creating very dangerous avalanche conditions. Travel in avalanche terrain is not recommended Tuesday.
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: Very 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: Very Likely
Expected Size: 1 - 1