Avalanche Forecast

A trace of new snow from Friday night sits atop a very strong and consolidated snowpack.Above freezing temperatures and rain in early February created spring-like snowpack conditions throughout the Olympics. A well-drained and relatively uniform snowpack exists in most location. There are currently no layers of concern in the snowpack.Height of snow varies greatly across the landscape. Sunny aspects have snowpacks half the depth of nearby shaded slopes.Recent warm and wet weather produced glide cracks on slopes with smooth ground surfaces. Some glide cracks resulted in large Glide Avalanches over the past week. These occurred in common locations such as Steeple, and the Steep-and-Icy avalanche paths.

NWAC pro-observer Matt Schonwald and NPS Rangers traveled in the Mt Angeles areas Thursday, 2/8. The snowpack was described as a fairly uniform, well drained late spring snowpack, lacking any distinctive layering. There were a few glide avalanches observed, likely releasing last Saturday during a rain event.

No significant avalanche problems exist in the region. A strong surface crust, uniform snowpack, and no layers of concern will make avalanches unlikely Sunday.  Use normal caution when traveling in the mountains. Always carry a beacon, shovel, and probe and use travel practices that minimize your exposure to avalanche terrain.Non-avalanche related hazards should be considered Sunday.Hard smooth surface crust will make stopping a fall in steep terrain very difficult.Large openings in the snowpack due to glide cracks, creeks, and around buried rocks have been reported. Falling into these holes creates a danger for backcountry travellers.

A compact and moisture-starved low moved quickly to the south of the forecast area on Sunday morning and now sits over west-central Oregon, having bypassed the Pacific Northwest of almost any moisture. As the low continues to track S-SE, mostly sunny skies and light northly flow predominate over the forecast area. There are a few notable exceptions such as at Hurricane Ridge where the northerly flow is backing clouds against the mountains, but the clouds should dissipate by the late afternoon hours. Clouds also still linger around Mt. Hood on Sunday afternoon and evening. The large offshore high pressure re-builds south of Alaska on Sunday. Sunday night the lower-level flow will switch to easterly, allowing colder area to infiltrate western Washington from the east side of the Cascades and BC coast range. Northerly flow continues aloft.On Monday, the offshore high pressure tilts into British Columbia, keeping the sunny weather  in place and with moderating temperatures over the Pacific Northwest. Light or calm winds are expected.On Monday night,  the high slides southward over the region, bringing further moderation aloft, with a good inversion likely to set up, particularly on the east slopes of the Cascades. Light or calm winds are expected.

On Tuesday the high pressure will be directly over the forecast area, bringing slightly spring-like weather to the region with light westerly flow developing. On Tuesday night, a shortwave trough splits the ridge, diving S-SW on a trajectory toward our region. The trough will be located over central British Columbia on Tuesday night. As the trough and associated frontal system approach, 9000 ft westerly winds will become moderate to occasionally strong over the central Cascades. Light to moderate snow will arrive, mostly after midnight for the Washington Cascades (mainly near and west of the crest) and Olympics.On Wednesday, the trough arrives in the early morning hours over the Pacific Northwest and digs deeper during the morning hours, before passing east of the area by nightfall. The west slopes of the Cascades should experiences moderate snowfall at low snow levels, with likely greater amounts in central-south Cascades and Hood regions. Wednesday night, snow showers end as a ridge rebuilds to the west and shifts east into our area. N-NW flow will predominate over the region.On Thursday, the ridge continues to edge into our region as any lingering light snow showers end. Fair weather returns.