Turnagain Pass

Light to moderate snowfall over the last three days has formed new slabs that will be easy to trigger in steep wind loaded terrain today.  In areas that have not received wind and on slopes under 35 degrees the new snow has been bonding well to older snow surfaces.  All reported avalanche activity in the past several days has occurred around the 2,800′ elevation.  This is due in large part to snow falling on a firm surface that has encouraged propagation across slopes.  While these avalanches have released snow in relatively large areas, the volume has been low enough that people have been able to avoid injury and burial.  While we have limited information from the upper elevations lately, snowfall amounts and winds have been high enough above 3,000′ to create dense slabs up to 18 inches in depth.  Throw into the mix new snow and winds today and slabs will increase in size and depth.  Sticking to slopes under 35 degrees and avoiding wind loaded starting zones will allow for enjoyable riding and skiing conditions today.

The deep slab problem is elevation dependent.  The snowpack between 1,000 and ~2,000 feet has been through four periods of warm temps, light rain and wet snow in the last month.  This has helped to change the structure of the snow at the ground to the point where it is generally not a concern.  However, above ~2,000 feet the snowpack is still in transition; snow pits have shown us that the weak snow at the ground is changing for the better.  However, as you gain elevation the weak snow at the ground is more intact and more of a problem to pay attention to.  Avoiding thin spots, steep rollovers, and terrain that doesn’t offer exit options is the best way to stay away from this problem.

It has been three weeks since a deep slab avalanche has been reported in the area.  It is now very difficult to affect weak layers at the ground.  The consequences still remain high, as a deep slab avalanche once triggered could entrain high volumes of snow and do a lot of damage.