Avalanche Forecast
Regions: Snoqualmie Pass.
Watch for loose wet snow conditions mainly on the volcanoes above treeline Friday.
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.
In most areas there generally wasn't any new snow Wednesday to Thursday morning and there won't be a significant change in the stable surface crusts and consolidated snow. So in most areas a change in the low avalanche danger is not expected.
But on the volcanoes above treeline use increasing caution if you see wet surface snow developing that is deeper than a few inches. In these areas loose wet snow avalanches should be possible mainly on solar slopes.
Remember that NWAC avalanche forecasts apply to terrain up to the Cascade crest level but not to the highest parts of the volcanoes where different more dangerous conditions are common.
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. Reports indicated thickening surface crusts on most slopes and some corn snow development on solar slopes. Lingering varied more winter-like surface conditions were still seen on north slopes at higher elevations. There have not been any reports of significant avalanches 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 the at Crystal and the most on the volcanoes especially Mt Baker. There may have been up to a few inches of new snow on the volcanoes above treeline especially at Mt Baker.
There was nearly no snowfall January to so far in March near and below treeline. The snowpack at lower elevations remains meager to non-existent.Â
The mid and lower snowpack west of the crest consists 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: Alpine.
Likelihood: Possible
Expected Size: 1 - 1