To reduce the chance of triggering avalanches, avoid areas where the wind has recently or is currently forming drifts and pillows. You will be most likely to find these avalanches on slopes exposed to the wind. Look for dune-like formations, hollow-sounding snow, and cracks in the surface from your machine or boards as clues you are on a wind slab.
This forecast is sponsored by Robert Brooks Painting.
Over the past four days, new snow and wind have created slabs. These wind slabs may be covered by newer lower density snow. There is plenty of loose snow on the surface available for the wind to transport. Increasing winds today will help grow existing slabs and create new ones. There was a snowmobile triggered wind slab yesterday in the Southern Wallowas, see the observation, here.
Several layers of buried surface hoar and crust/facet combinations exist in the upper half of the snowpack. These layers are becoming harder to identify and seem to be gaining strength. While this is good in the long run, it means currently they aren't giving us obvious clues such as whumpfing. To identify these weak layers you must dig down and perform stability tests. Forecasters remotely triggered one of these persistent slab avalanches while snowmobiling in the Blues on Tuesday, you can watch the videos here and here.
While unlikely, the chance of triggering a deep persistent slab avalanche still exists. This is most likely in areas of shallow snow where weak snow lingers at the base of the snowpack.
Increasing winds today will grow new slabs. This wind will redistribute snow adding weight and stressing the persistent weak layers that exist in the snowpack. As winds increase this afternoon the avalanche danger will begin to increase. Travel will likely become unpleasant in areas exposed to the strong Southerly winds.
