Avalanche Forecast
Issued: Mar 12th, 2015 9:53PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Loose Wet.
NWAC,
Northwest Avalanche Center
East of the crest Friday watch for unlikely small wet loose avalanche conditions mainly on solar aspects.
Summary
Detailed Forecast
A mostly sunny warm day should be seen on Friday with freezing levels rising to around 9,000 feet in the north and around 10-11,000 feet in the south.
East of the crest there wasn't any new snow Wednesday to Thursday morning so there should not be a significant change in the stable surface crusts and consolidated snow. East of the crest Friday watch for unlikely small wet loose avalanche conditions mainly on solar slopes.
Due to the low snowpack, especially below treeline, watch for terrain hazards such as open creeks, partially covered rocks and vegetation. Many areas below treeline do not have enough snow to cause an avalanche danger.
Heads up for the expected rain event on Saturday.
Snowpack Discussion
The latest warm dry period of the winter was seen from the start of March through Tuesday. This was mainly a period of consolidation and stabilizing throughout the Cascades. Reports indicated thickening surface crusts on most slopes and some corn snow development on solar slopes.
The North Cascade Mountain Guides were in the Harts Pass and Washington Pass area over the weekend. They reported some cool varied surface snow on north slopes, corn snow on south slopes, and no stability concerns. The snow study plot on a north aspect at 6600 feet above Varden Creek measured a snow depth of nearly two and a half meters! They also re-affirmed the overall low avalanche danger.
There have not been any reports of significant avalanches in the Cascades for some time.
A weak front crossed the Northwest Wednesday to Thursday morning. NWAC sites west of the crest near and below treeline picked up anywhere from about .1 to 1.6 inches of rain with some snow above treeline on the volcanoes. But very little fell east of the crest.
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: Alpine.
Likelihood
Expected Size
Valid until: Mar 13th, 2015 9:53PM
