Issued: 8:06 AM PST Sunday, February 4, 2018
by Dennis D'Amico

NWAC avalanche forecasts apply to backcountry avalanche terrain in the Olympics, Washington Cascades and Mt Hood area. These forecasts do not apply to developed ski areas, avalanche terrain affecting highways and higher terrain on the volcanic peaks above the Cascade crest level. 

8 AM Update: Changed Wet Slab Avalanches to Wind Slab Avalanches Above Treeline in Mt. Baker Zone (West Slopes North)

Warm weather will create wet surface snow conditions at all elevations. Stay off of steep slopes with wet surface snow where you might trigger a Loose Wet avalanche. Avoid traveling on or below Cornices. Warm temperatures and recent rain will make it more likely for these large blocks of snow to fail.

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Avalanche Problems for Sunday

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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.

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Cornices are easy to identify and are confined to lee and cross-loaded ridges, sub-ridges, and sharp convexities. They are easiest to trigger during periods of rapid growth (new snow and wind), rapid warming, and during rain-on-snow events. Cornices often catch people by surprise when they break farther back onto flatter areas than expected.

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Forecast for Sunday:

Light rain and continued mild temperatures on Sunday will maintain wet snow and avalanche conditions at all elevations in the Olympics.

Loose wet avalanches are possible to trigger on steep slopes with wet surface snow. Avoid slopes where avalanches may carry you into dangerous terrain such as over a cliff, into a creek, or down a gully. Watch for new rollerballs and pinwheels as signs that triggering a loose wet avalanche is becoming more likely.

Large cornices exists primarily on NW-NE aspects along ridgelines in the Hurricane Ridge area. Mild air temperatures and rain will make these massive blocks of snow more likely to fail. It is very difficult to predict when and where cornices will fall. Avoid traveling on or below cornices during this mild weekend.

Several glide cracks have been reported recently by NPS rangers. Glide avalanches occur in locations where wet smooth ground surfaces allow the entire snowpack to avalanche. Glide avalanches are highly unpredictable and as their releases generally are not tied to peak warming or rainfall. If you see glide cracks on a slope, avoid traveling on or below that terrain. While you are unlikely to trigger a glide avalanche, a glide avalanche would be large and deadly.

Avalanche Summary:

Saturday morning's sunbreaks and mild temperatures were followed by periods of light rain in the afternoon. Significant snowpack settlement continues to occur in the Hurricane Ridge area with the recent warm and wet weather. On Friday, several natural loose wet avalanches were observed at all elevations.

Large cornices developed during the last two weeks of January along ridgelines near and above treeline.

The recent warm and wet weather has produced glide cracks on slopes with smooth ground surfaces. Observations indicate glide cracks in common locations such as 20th of June, Steeple, and the Steep-and-Icy avalanche paths.


NWAC pro-observer Matt Schonwald and NPS Rangers traveled in the Mt Angeles areas Friday. They observed moist to wet surface snow up to 6000 feet. Loose wet avalanches were seen releasing during sunny breaks around mid-day. They identified and avoided traveling near or below large cornices.

No Corresponding Mountain Weather Forecast Available


This Backcountry Avalanche Forecast is provided in conjunction with the US Forest Service, and is intended for personal and recreational purposes only. Safe backcountry travel requires preparation and planning, and this information may be used for planning purposes but does not provide all the information necessary for backcountry travel. Advanced avalanche education is strongly encouraged.

The user acknowledges that it is impossible to accurately predict natural events such as avalanches in every instance, and the accuracy or reliability of the data provided here is not guaranteed in any way. This forecast describes general avalanche conditions and local variations will always occur. This forecast expires 24 hours after the posted time unless noted otherwise.