Avalanche Forecast

Issued: Feb 9th, 2019 10:17AM

The alpine rating is below threshold, the treeline rating is below threshold, and the below treeline rating is below threshold.

Northwest Avalanche Center NWAC, Northwest Avalanche Center

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Cascades - South East.

A potent winter storm impacted the East-South Zone on Saturday. While we don’t have a lot of specifics for this area, we know it likely fell on a very weak snowpack and has created some dangerous avalanche conditions. This is a time to be extremely cautious and avoid all open slopes greater than 35 degrees. You may see avalanches even at lower elevations and in the sagebrush country further east of the mountains.

Summary

Discussion

Snow and Avalanche Discussion

This was one of the biggest single storms to impact the zone this season. The snow was so light, and the winds so strong that the weather stations may have done a poor job of measuring the water weight of this new snow. We suspect 8-10” of snow fell Friday into Saturday. There is quite a bit of uncertainty in this forecast. We suspect the snowpack is highly variable and contains several weak, old snow layers. As the snowpack has grown, so have the potential size of any triggered avalanches. This is a time to be conservative as you travel. Stay off of open slopes greater than 35 degrees.

There are three things to key into as you travel Sunday.

  1. If you see natural slab avalanches, experience sudden collapses, or see long shooting cracks, stay out of all nearby avalanche terrain, including where avalanches can run and stoop.

  2. Wind loaded slopes are suspected to be the most dangerous. Use visual clues such as snow drifts, fresh cornices, and uneven snow surfaces to find areas where the wind transported the snow. When you see these clues, avoid steep slopes nearby.

  3. Low elevation avalanches: The recent storms have brought recreatable snow to lower elevations. These snowpacks also contain the same weak layers we are concerned about in nearby regions. Don’t think, just because you are out in lower hills, you are safe from avalanches.

Forecast Schedule and No Rating

At this time, we do not have enough specific snowpack information to issue an avalanche hazard rating for the East Slopes South zone. However, even when No Rating is applied, applicable avalanche conditions and backcountry travel advice will be provided throughout the season. When weather systems produce very dangerous avalanche conditions in adjacent zones, NWAC will issue an avalanche warning for this zone as well.

Snowpack Discussion

Regional Synopsis coming soon. 

Valid until: Feb 10th, 2019 10:17AM

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