The mountains generally contain two very different snowpacks. At lower elevations, you will likely find bare ground or a very thin and wet snowpack. At upper elevations, drier and colder snow may exist. These high elevations are where you are most likely to encounter avalanche concerns.
Anticipate avalanches if you encounter 6 inches or more of recent snow accumulation.
Use small test slopes to check the bond between any recently accumulated snow and older snow. Look for signs of instability such as cracks shooting through the snow or whumpfing collapses.
Shallow snow coverage exists. Watch for shallowly buried rocks, stumps, crevasses, and creeks.
Make sure everyone in your group is carrying and knows how to use avalanche rescue gear (transceiver, shovel, and probe).
Snow and Avalanche Discussion
You may find the transition from the thin low elevation snowpack to the drier deeper snowpack occurs at different elevations across the Cascades. This may occur as low as 5000’ in the north to 6500’ in the south.
The snow at low and middle elevations became thin and wet across the region due to the onset of warmer temps and mixed precipitation this past week. Travel may be very difficult at these elevations due to numerous early season obstacles and bare ground. This pattern will continue at lower elevations this weekend.
At upper elevations, a deeper and drier snowpack may exist. Expect snow showers the first part of the weekend to add a few inches to the existing snowpack. Take time and inspect the interface between the new and old snow. If poor bonding exists, you may find avalanches on similar slopes.
Soft snow and early season hazards at Twin Lakes on 12/5/19. Photo: Pete Durr
Keep up with the daily Mountain Weather Forecasts as the weekend progresses. If you head into the mountains, travel cautiously and be prepared to make your own observations and snowpack assessments.
During the run up to winter, NWAC forecast staff will monitor snow, weather, and avalanche conditions, and issue an updated Conditions Report at 6 pm every Monday, Wednesday, and Friday until daily avalanche forecasts begin.
What did you see? Share your observations with NWAC and the backcountry community.