Avalanche Forecast

Discussion 

Low snow conditions continue to limit the overall avalanche hazard in the East Slopes South forecast zone. Wednesday saw some warming, but little new accumulation. 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.  

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 20181211

Welcome winter!!!

The NW snowpack is evolving quickly and a near constant pattern of winter storms with fluctuating freezing levels is making things interesting for our 1st week of forecasting.

Here’s what we know:

• Tuesday saw a significant avalanche cycle.

• We have a lot of new snow...2-3’ above 4500ft.

• We’ve gotten a lot of wind.

• We have weak layers near the ground.

• We are going to get more snow before the weekend.

All in all that’s enough to indicate that dangerous avalanche conditions will persist over the next couple of days. That said, it is early season and the flavor of avalanche you may run into is likely a function of elevation, timing, and dumb luck.

Here are some basic emerging patterns:

• Storm total (Monday morning to Wednesday evening):

  • Mt. Baker: 24”

  • Washington Pass: 22”

  • Snoqualmie Pass: 10”

  • Paradise: 17”

  • Mt. Hood Meadows: 10”

• Upper versus Lower Elevations: The change in the snowpack is still 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 awhile.

• East versus West: Loading along the East slope has been more incremental, and a  variety of buried facet and surface hoard layers may be found. This is most pronounced near WA Pass. Although significant snowfalls and precip totals have resulted in thicker, more homogeneous snowpack in the western zones, lingering weak layers near the ground will persist through the week.