Freshly deposited heavy snow will create dense slabs at upper elevations. This newly deposited snow may sit on crusts formed by warming. If you find dense slabby snow, chose lower-angle slopes (less than 30 degrees).
Consistent snowfall and fluctuating temperatures have created dense slabs of snow. These dense slabs sit upon crusts and varying densities of snow. As more snow is added the likelihood of triggering a storm slab avalanche increases. If you find dense snow sitting on a crust or lower-density snow, move to lower-angle terrain (< 30 degrees)
Changes in temperature and snow switching to rain have created crusty surfaces. These crusts allow new snow to slide downhill easily. As the day warms or snow switches to rain, the chance of a wet loose avalanche increases rapidly. Look for pinwheels, rollerballs and trees dripping as early signs things are warming up. If you observe these conditions seek slopes less than 30 degrees.
Since Tuesday afternoon, the mountains have received 6-12" of new snow. The Blues, Elkhorns, and Southern Wallowas picked up more snow during this storm with snow totals close to 1'. The Northern Wallowas received less, closer to 6". Despite the differences in snowfall totals, the overall weather patterns and snowpack changes have been similar.
As we near the end of March the snow is more wet and warm. Daytime temperatures are higher and even brief appearances from the sun can change the snow surface. These conditions have resulted in an upper snowpack layered with small density changes and crusts. These crusts can create good bed surfaces for avalanches to run on and can sandwich snow creating weak layers, as found here.
As temperatures increase and if the sun pokes through the clouds the chance of wet loose avalanches increases. This avalanche problem is a consistent possibility in spring. Stay alert to changes in temperature and the effect of the spring sun.
