Wind Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 1–2
Old wind slabs are now mostly non reactive. I did not see much blowing snow near treeline on Thursday, mostly because the new snow was so wet and sticky and not easily moved by the wind. As the temperature drops overnight the new snow will be lighter and more easily moved by the wind. New wind slabs will grow throughout the day. Wind can pile up snow 5 times deeper or more compared to the snow that has accumulated from the storm. Most wind slabs will be small, however some isolated pockets of terrain that catch a lot of blowing snow could produce large avalanches. Blowing snow is a good indicator of where wind loading is occuring. Look for a pillowy drifts or a wavy surface texture as clues to where wind slabs have formed.
Wind slabs may show up in places like clearings and areas with sparse trees even below treeline. Remember burned areas and slopes with dead trees can experience a big wind affect and get a lot of wind deposited snow.
Utilize small features or low angle terrain to evaluate the wind slab problem. Look for cracking in the surface snow. Anytime you observe cracking in wind drifted snow, or if you see signs of previous avalanches, these are good indicators that you can trigger an avalanche.
This problem can be avoided by sticking to the sheltered slopes where little wind effect has occured.