Register for an account and never miss a forecast again!
RegisterRegister for an account and never miss a forecast again!
RegisterFeb 2nd, 2015–Feb 3rd, 2015
.
Heightened avalanche conditions are expected on lee aspects, mainly near and above treeline, with shallow but perhaps sensitive wind slab.
Little or no precipitation is expected early Tuesday, with light rain and snow increasing in the afternoon.
Shallow storm slabs formed Sunday and Monday may be poorly bonded to old surface crusts, especially near and above treeline on lee aspects.
Deeper persistent weak layers are still considered unlikely for human triggering along the east slopes.
During the weekend of Jan 24-25th, a warm weather system caused high snow levels and rain east of the crest. NWAC sites east of the crest had up to an 1 inch of rain. This caused loose wet avalanches, some possible wet slab avalanches and consolidation. Mild or sunny weather settled in last week at upper elevations with low clouds or fog along the lower slopes.
Werak frontal systems crossed the PNW Sunday and again Monday, producing generally light amounts of new snow, highest in the northeast Cascades. Moderate SW winds at crest level likely built shallow new wind slab near and above treeline along the east slopes nearest the Cascade crest.
Recent Observations: Surface hoar growth was seen between about 3000-4500 feet where recent low clouds or fog have persisted east of the crest this week. Some near surface faceting has been reported on non-solar slopes, along with a varying degree of supportable crusts. These weak layers may have been buried by light snowfall Sunday and should be tracked moving forward.
On Jan 25th, the Mission Ridge ski patrol reported that depth hoar at 45 cm below the surface was becoming rounded but still failed on isolation. NWAC pro-obs or North Cascade Guides reports last week in the northeast and central east zones have found the January 15th facet/crust layers at 40 cm-1 m below the surface with the facets starting to turn to rounded grains and not reactive or not releasing in pit tests. So the January 15th facet/crust layers expected in the northeast and central east zones appears to be strengthening and stabilizing.
NWAC pro-observer Tom Curtis was at 7500 ft on Mt Cashmere in the Wenatchee Mountains on Wednesday and found a local facet/crust combo buried on a lee slope next to a ridge crest under 35 cm of thick, surface crust and 1F-P snow. This sort of slab could be very hard for a skier to trigger, but could be possible, perhaps with a large sudden load, such as snowmobiles.