Avalanche Forecast

Discussion 

Low snow conditions continue to limit the overall avalanche hazard in the East Slopes South forecast zone. Near and above treeline, we may be approaching the snow depth threshold for avalanches.

We have no information about the existence of a Persistent Slab avalanche problem in this zone. However, in adjacent zones, weak early season snow has been buried by recent storms, creating dangerous avalanche conditions. If entering avalanche terrain, mitigate the high uncertainty by traveling cautiously and choosing moderately angled and supported terrain away from overhead hazards.

Recent winds may have formed wind slabs on lee slopes near and above treeline. Watch for evidence of recent wind transported snow, such as firm surface snow, deep drifts, and wind scoured areas. When you encounter firm surface snow on steep slopes, be aware that avalanches may break above you. 

Forecast Schedule

General avalanche and snowpack information will be provided during the winter. However, at this time we do not have enough specific snowpack information to issue an avalanche hazard rating for the East Slopes South zone.  

Dangerous and fickle avalanche conditions remain as active weather continues into the week. Thick slabs of new snow (2-5 feet) are perched above a weak layer of faceted crystals. Avalanches triggered on this layer could be very large and life-threatening.

Reports continue to come in of very large natural and triggered avalanches in the northern and eastern zones. For perspective, several of these slides have been classified as D3, or large enough to destroy a house. You can find similar snowpack structure responsible for these avalanches in many other locations throughout the Cascades, including Stevens and Snoqualmie Passes.

Anyone accessing alpine areas should limit their exposure to areas where avalanches start, run and stop. In some places, the weak snow will talk to you by whumpfing and cracking. In other places, the heavy blanket of new snow is thick enough that it can give a false sense of stability while it masks the dangerous layering below.

Approximate snow totals from 12/10 - 12/16:  

• Mt. Baker: 75”

• Washington Pass: 35”

• Stevens Pass: 42”

• Snoqualmie Pass: 36”

• Paradise: 51”

• Crystal Mt Base: 29”

• Mt. Hood Meadows: 21”

• Olympics: mix of rain and snow, no net gain

The change in the snowpack is pretty dramatic with elevation. The height of snow decreases rapidly below 4500’ at Baker and Washington Pass, 5500’ at Crystal/Rainier. The Passes have better low elevation coverage, but it's still pretty thin below 4000’. With additional warm storms in the forecast, this pattern is expected to continue for a while. Mt. Hood and Hurricane Ridge have low snow coverage below 5000’.

If you're out in the mountains, please let us know what you see.

Be cautious and get home safe.