Avalanche Forecast

Discussion 

Low snow conditions continue to limit the overall avalanche hazard in the East Slopes South forecast zone. Little new snow accumulation has occurred since Tuesday. Recent warming likely helped settle any sensitive storm layers. A strong storm on Tuesday brought plenty of water and rain, but unfortunately little in the way of new snow below treeline due to near or above freezing temperatures. Near and above treeline, we may be approaching the snow depth threshold for avalanches.  

Throughout the remainder of the Washington Cascades, weak early season snow has been preserved and buried by recent storms. This has caused some unusually large and hard to predict avalanches over the past few days. There is large uncertainty as to the extent of this problem, especially in this zone where little information is available. The best advice is to travel very conservatively limiting exposure to start zones or where avalanches can run or stop. Triggering an avalanche on this layer would result in a large and potentially life-threatening avalanche. 

Forecast Schedule

General avalanche and snowpack information will be provided for this area 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.  

 

Regional Synopsis 20181214

 

We made it through our first strong winter storm and are headed into a weekend with dangerous and fickle avalanche conditions. 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 explosives 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.

 

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 - 12/14:  

• Mt. Baker: 55”

• Washington Pass: 29”

• Stevens Pass: 37”

• Snoqualmie Pass: 28”

• Paradise: 38”

• Mt. Hood Meadows: 13”

• Olympics: mostly rain

 

The change in the snowpack is pretty dramatic with elevation. 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.

 

Be cautious and get home safe.