As rain soaks last week's powder, avalanches are likely on steep slopes.
The weather forecast for Monday calls for 3/4 inches of rain. Rain on previously dry snow is a good setup for Wet Slab avalanches. Observers have been finding poorly developed faceted layers in our upper snow pack, and these layers my be activated with increased loading and water percolating to their depth. For this reason I would particularly avoid steep, poorly supported, North facing slopes.
Rain on snow often leads to Wet Loose avalanches as the amount of free water increases and the amount of ice (snow) decreases. Watch steep, poorly supported terrain as that will be the first place these avalanches occurr. The size of Wet Loose avalanches depends upon the depth to which rain water and melting have extended into the snowpack. Wet Loose avalanches may occurr on their own, but they can also occurr in concert with Wet Slab avalanches.
Last week's snowfall left us with a variety of surface conditions because of variable wind direction and sun. Another 6-8 cm. of heavier snow fell Saturday night and Sunday. Observers have been finding some poorly developed faceted snow on protected North slopes that is now 20-35 cm. deep (several cm. above the prominent melt-freeze crust). Significant rainfall is forecast for the central Cascades below 8,500 ft. This weak snow is a great candidate for where Wet Slabs could fail.
