Dashboard Regions Weather Stations Radar Alerts Glossary
Contact About
Log In

Register for an account and never miss a forecast again!

Register

Avalanche Forecast

Archived

Feb 9th, 2015–Feb 10th, 2015

Alpine
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches possible, human triggered probable.
Below Treeline
Natural avalanches possible, human triggered probable.
Alpine
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches possible, human triggered probable.
Below Treeline
Natural avalanches possible, human triggered probable.

Regions

Mt Hood.

A transition from the recent wet warm weather to dry warm weather will begin on Tuesday. You will need to watch for a variety of snow and avalanche conditions on Tuesday.

Detailed Forecast

The upper ridge will begin to rebuild over the west US on Tuesday. At Mt Hood this should cause decreasing west winds with light showers decreasing Tuesday morning and ending Tuesday afternoon.

New wind slab from the storm on Monday maybe found mainly on steep NW to E slopes near ridges above treeline. Watch for firmer wind transported snow.

New storm slab seems possible where there is more than a few inches of snowfall in areas with light wind.

Any cooling will be limited Tuesday morning and temperatures will be on the rise again by Tuesday afternoon. More loose wet avalanches  are likely on steep mainly solar slopes.

As a result of the unseasonably low snowpack, especially at lower elevations, watch for terrain hazards such as open creeks, partially covered rocks and vegetation.

Snowpack Discussion

A series of fronts in an atmospheric river has been crossing the Northwest. Mt Hood has seen about 2 inches of WE mostly as rain from about February 5th-10th with about 10-12 inches of melting, consolidation and stabilizing of the snowpack.

No avalanches were seen or reported by the Mt Hood Meadows pro-patrol through Sunday afternoon with recent wet snow well bonded and not causing any significant loose wet problems near and below treeline.

But a filling low pressure system crossed  mainly the south Cascades and Mt Hood area on Monday. This is caused the most wind and rain or snow in the far south Cascades and at Mt Hood on Monday. A brief minor drop in snow levels should be seen at Mt Hood Tuesday morning.

The mid and lower snowpack at Mt Hood should consist of layers of stable consolidated rounded grains or melt forms and crusts from multiple warm periods this winter.

 

Problems

Wind Slabs

Wind Slab avalanches are the 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.

Storm Slabs

Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). 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.

Loose Wet

Loose Wet avalanches are the 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. 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.