Avalanche Forecast

The recent clear weather is giving way to increasing clouds and a return to a few light showers Sunday afternoon and should persist into Monday. Freezing levels should remain low.

A heightened avalanche danger should apply to wind-loaded slopes near and above treeline where east-southeast winds continue to build new wind slab on a variety of aspects. After several days of strong east winds, most of the available surface snow should have been stripped from the surface. But it may still remain possible to trigger a small slab avalanche on a loaded convex roll or some unsupported slope. Look for recently transported snow further downslope from ridgelines than you might expect.

The new wind slab is expected to be less of an issue in the North Cascades where winds continue to be less. 

The latest extended storm cycle in late December, deposited 5-9 feet of snowfall along the west slopes ending December 24th. Since then, light additional accumulations of snow were followed by a clear, cold period under high pressure. Since the snowdepth maximum was reached on Christmas, most west slope areas have settled some 2-3 feet. Widespread surface hoar or near surface faceting has been reported in sheltered areas over the current stretch of high pressure. 

Surface snow conditions in many areas and on many terrain types have undergone significant changes over the past several days. Strong east winds have transported loose surface snow, building wind slab on a variety of aspects over the last few days, primarily in the central and south Cascades, including the Cascade Passes. The North Cascades, including the Mt. Baker area, have had less wind effect, but have experienced warmer temperatures, likely inducing some loose-wet slides over the last few days. 

On shaded and wind protected slopes, settled power is still providing fine conditions, but becoming more scarce and seekers need to look a bit harder to find it.    

Preliminary Granite Mountain Avalanche Fatality Information: Through preliminary interviews with SAR teams, a hiker died on Granite Mountain near Snoqualmie Pass Thursday, likely due to a wind slab avalanche on a west facing slope near treeline. The hiker was recovered by SAR on Friday morning and found on top of the avalanche debris. It is not known yet whether the slab was natural or human triggered.   

Recent avalanche and snowpack observations: 

Since midweek, recently formed wind slabs were triggered in numerous areas, on a variety of aspects producing mostly small, shallow slides from 6-12 inches in general. 

Moderate east transport winds were observed from Snoqualmie south to Mt. Hood.  NPS rangers from Mt. Rainier reported several D1/R1 (small) skier triggered wind slab on west aspect near treeline Thursday. Two skier triggered wind slabs were reported near Kendall peak (Snoqualmie area) on the north and west aspects. Both were small but one ran a fair distance and took a skier for a ride. 

The MRNP Paradise backcountry ranger reported two harder wind slab releases Friday on the west aspect off of Pan Face, and at least 1 wasskier triggered. In a nearby pit, the ranger determined the wind slab was about 30 cm (1 ft) deep and 1F to P hardness. He also reported a skier a small triggered wind slab release on a SW aspect in the Nisqually area.