Register for an account and never miss a forecast again!
RegisterRegister for an account and never miss a forecast again!
RegisterDec 16th, 2018–Dec 17th, 2018
.
Continued snow and wind will keep avalanche danger elevated. You can trigger large and surprising avalanches that could break widely across terrain features. Careful route finding and cautious decision-making are essential.
A series of storms over the past week delivered 3 feet of new snow to the Washington Pass area. A widespread natural avalanche cycle occurred on December 11th. More snow and wind in the forecast will test buried weak layers of surface hoar and facets. Observers experienced shooting cracks and collapses over the weekend. Recent stability tests also confirm the potential for propagation on these weak layers within the snowpack.
Limited information exists for the East North Forecast Zone. If you head out in this area, please send us your observations.
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.