Avalanche Forecast
Regions: Mt Hood.
The wet surface layers should drain quickly Monday and strong winds should also help to firm the surface snow, all limiting the likelihood of wet snow avalanches Monday. Watch for wind transported snow at the highest elevations.
Detailed Forecast
Moderate to heavy rain and snow is expected with strong winds and moderately high freezing levels overnight Sunday. The heavy precipitation will shift north of Mt Hood Monday, though freezing levels will remain high.Â
Many steep slopes may have released naturally by Monday due to warming and rain, locally lowering the danger on those slopes, however on slopes that have not released, natural or triggered avalanches should remain possible Monday.  Â
Wind slabs may have built at the upper elevation zones of the forecast on lee slopes below ridges, mainly N-SE facing.
Loose-wet avalanches will be a concern on steeper slopes at lower elevations. Watch for wet snow that gets deeper than a few inches.
The wet surface layers should drain quickly Monday and strong winds should also help to firm the surface snow, all limiting the likelihood of wet snow avalanches Monday.
Snowpack Discussion
Weather and Snowpack
The warmest weather of the winter occurred this past Sunday through Wednesday with extended temperatures climbing into the 50's, with some excursions into the 60's!  A warm front brought periods of rain to the Mt Hood area Thursday night through mid-day Friday, with snow levels falling to 5500 ft after the frontal passage Friday afternoon. Further cool showers Saturday  and Saturday night combined to deposit storm snow amounts ranging from about 6-12 inches as of Sunday morning.
Warming changed snow to rain to high elevations Sunday. Heavy rain Sunday and Sunday afternoon caused wet snow conditions by Sunday afternoon.  Â
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Recent Observations
Limited loose wet avalanches were reported Sunday on Mt Hood by the pro-patrol. The recent warm weather has allowed the rain Sunday to drain well from surface layers, helping limit the likelihood of wet snow avalanches.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.
Elevations: Alpine.
Likelihood: Likely
Expected Size: 1 - 1
Loose Wet
Release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. They generally move slowly, but can contain enough mass to cause significant damage to trees, cars or buildings. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.
Travel when the snow surface is colder and stronger. Plan your trips to avoid crossing on or under very steep slopes in the afternoon. Move to colder, shadier slopes once the snow surface turns slushly. Avoid steep, sunlit slopes above terrain traps, cliffs areas and long sustained steep pitches.
Several loose wet avalanches, and lots of pinwheels and roller balls.
Loose wet avalanches occur where water is running through the snowpack, and release at or below the trigger point. Avoid terrain traps such as cliffs, gullies, or tree wells. Exit avalanche terrain when you see pinwheels, roller balls, a slushy surface, or during rain-on-snow events.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Possible
Expected Size: 1 - 1