Register for an account and never miss a forecast again!
RegisterRegister for an account and never miss a forecast again!
RegisterApr 5th, 2018–Apr 6th, 2018
Olympics.
Wet snow conditions will persist with Loose Wet avalanches now possible at all elevations. Avoid slopes with terrain traps where you see evidence of new rollerballs, pinwheels, and small Loose Wet avalanches. Recent rain and warm temperatures have weakened Cornices so give them a wide berth and be aware of overhead hazard. Older persistent weak layers may still exist in the upper snowpack around Hurricane Ridge. Use caution on open slopes greater than 35 degrees on N-E aspects near and above treeline.
Relatively dry and warm conditions are expected Friday. Wet snow conditions will persist with Loose Wet avalanches now possible at all elevations. In isolated areas, Loose Wet avalanches may become large if they gouge down to deeper layers. Avoid slopes with terrain traps where you see evidence of new rollerballs, pinwheels, and small Loose Wet avalanches.
Recent rain and warm temperature have weakened Cornices. Give Cornices a wide berth if traveling along ridgelines as they often break back further than expected. Be aware of overhead hazard if traveling on slopes with Cornices above as they may fail naturally or be human-triggered.
Older persistent weak layers may still exist in the upper snowpack around Hurricane Ridge. It can be difficult to assess and manage Persistent Slab avalanches. You can use snowpack tests to confirm the presence of these weak layers, however, they are not a decision making tool. You can avoid triggering a Persistent Slab avalanche by staying off of open slopes greater than 35 degrees on N-E aspects near and above treeline.
Recent shallow Wind Slabs formed earlier in the week may still exist in isolated areas above treeline (above ~6000 ft) on lee slopes. Use visual clues such as blowing snow, fresh cornices, and cracks in the snow all indicate you could trigger a Wind Slab avalanche.
Periods of light rain and a rising snowline allowed wet snow conditions to extend into the near and above treeline elevation bands Thursday. On Wednesday, shallow amounts of wet snow accumulated above about 5000 ft.
Three to six inches (8-15cm) of snow fell at Hurricane Ridge last Sunday through Monday morning. Light to moderate winds during the storm transported the new snow, likely forming new shallow and reactive wind slabs at higher elevations. This new snow fell on melt-freeze crusts in most locations.
Older weak snow has been observed on N-E aspects near and above treeline. Weak sugar facets may be found just above a melt-freeze crust. This layer is generally 1.5 to 2 feet (45-60cm) below the snow surface. Regular above freezing day-time temperatures over the past 10 days since the last reported avalanche at this interface have likely helped stabilize these older weak layers, but more information is needed to put Persistent Slab concerns to rest.
There are no other significant layers of concern in the snowpack at this time.
Observations
No avalanche activity has been reported in the Hurricane Ridge area over the last week.
Last Friday 3/30, NPS Rangers performed snowpack tests on a NNE aspect at 5,000 ft. They reported test results indicating propagation on a layer of weak old snow about 2 ft below the surface.
On Thursday, 3/29 NWAC professional observer Matt Schonwald saw evidence of two recent slab avalanches releasing on steep convexities on NE aspects between 5200-5400 ft. These avalanches released on a weak layer, poorly bonded to a hard crust. Several snowpack tests on this layer confirmed the propensity for avalanches to propagate.