Avalanche Forecast
Regions: Mt Hood.
The main problem to watch for at Mt Hood on Monday should be possible loose wet avalanches.
Detailed Forecast
An amplifying upper ridge over the US and BC coastal waters will dominate the weather the next few days. This will cause sunny, warm weather in the Olympics and Cascades Monday and early next week.
The main problem to watch for at Mt Hood on Monday should be possible loose wet avalanches. Watch for initial rollerballs or surface wet snow deeper than few inches. While this is expected mainly on solar slopes midday watch for it on other aspects as well. Overnight cooling and surface refreezing will limit this problem on non-solar slopes and during the night and morning hours.
As a result of the overall low snowpack, especially below treeline, watch for terrain hazards such as open creeks, partially covered rocks and vegetation.
Snowpack Discussion
Warm and wet southwest flow directed a series of fronts across the Northwest from about February 5th-10th.This brought less rain to Mt. Hood compared to areas in the WA Cascades and led to further overall snowpack melt at lower elevations. Then the last system in the series crossed the south Cascades late Monday and early Tuesday. This caused strong winds and deposited 15 inches of new snow at 6600 feet at Mt Hood Meadows.
Warmer temperatures have been seen at Mt Hood the past few days and today. Due to the ongoing warm weather the last snow will probably not be distinguishable from earlier snow on many slopes.
Avalanche control at Meadows on Tuesday gave numerous size 1-2 wind and storm slab avalanches on lee slopes but with limited propagation. Similar wind slab concerns were reported on lee east aspects west of Timberline Tuesday via the NWAC Observations page.
These storm and wind slab layers should have stabilized under warming temperatures and sunshine.Â
NWAC pro-observer CJ Svela was at Timberline on Friday and found possible small loose wet avalanche conditions on solar slopes. He also found stable melt forms and rounded grains in the upper snowpack. Another report via the NWAC Observations page indicated no avalanches were observed at Mt Hood though a specific location was not given.
The Meadows pro-patrol reports a good refreeze of surface snow this morning and no avalanches today.
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.
Avalanche Problems
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: South East, South, South West.
Elevations: All elevations.
Likelihood: Possible
Expected Size: 1 - 1