Register
Get forecast notifications
Create an account to receive email notifications when forecasts are published.
Login
Archived

Avalanche Forecast

Dec 16th, 2018–Dec 17th, 2018
Alpine
Below Threshold
The avalanche danger rating in the alpine will be below threshold
Treeline
Below Threshold
The avalanche danger rating at treeline will be below threshold
Below Treeline
Below Threshold
The avalanche danger rating below treeline will be below threshold
Alpine
Below Threshold
The avalanche danger rating in the alpine will be below threshold
Treeline
Below Threshold
The avalanche danger rating at treeline will be below threshold
Below Treeline
Below Threshold
The avalanche danger rating below treeline will be below threshold

Regions: Olympics.

Early season conditions exist in the Hurricane Ridge area with large variations in snow cover. On slopes with enough snow to present an avalanche hazard, consider if a small avalanche could cause injury due to exposed rocks and vegetation. 

Discussion

Discussion 

Low snow conditions continue to limit the overall avalanche hazard in the Olympics. Snow cover varies widely by elevation and especially aspect.

On windward southerly facing terrain, much of the area is void of snow cover. On shaded and wind loaded north through east aspects, snow depths averaged about 4 feet as of Sunday afternoon.

Fresh wind slabs may have formed on lee aspects above 6000 feet, but we have no direct observations about their distribution or likelihood of triggering due to recent storm conditions and road closures.  

Forecast schedule

For the 2018-19 winter season, avalanche hazard ratings will be issued for the Olympics Friday through Sunday and during holidays.

On days that the Hurricane Ridge road is closed, No Rating will be applied. We will continue to provide general snowpack and weather summaries for the Hurricane Ridge area even when No Rating is issued. 

Snowpack Discussion

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.