Turnagain Pass

We received the lower end of forecasted snow amounts with only 5-7 inches falling across the advisory area. This might not seem significant but there are few important factors to keep in mind. First this fell on weak surface snow, second it came in with easterly winds blowing in the 20s and gusting as high as 60mph on Sunburst, third there was already soft snow available to transport and finally the temperatures were steadily rising throughout the storm so the snow will be upside down. Colder snow will be under warmer heavier snow. Then put this all on top of the surface hoar that has been the culprit in all of the avalanche activity in the last two weeks. This surface hoar sits 1-2 ft below the surface and has shown that it still has the potential to avalanche. It now has additional load on top of it and may have a more connected slab due to wind-loaded snow.  Some slopes have slid on this layer and some haven’t. This combination warrants caution. It may be triggered remotely and may let you get out onto the slab before it breaks. The new snow and wind might have been the tipping point or your weight might be when you get onto the slope. 

Today it will be important to look for recent avalanches, cracking and collapsing (whumpfing). In addition look for wind deposition, wind slabs, newly formed cornices and places where you feel stiffer snow over soft snow. Keep slope angles low and pay attention to what is above and below you. Remember the buried surface hoar when you are making your slope decisions. 

Buried surface hoar picture taken November 19th. Photo: Wendy Wagner

This photo was taken yesterday, November 30th on Manitoba and the same layer is still visibly intact and still showed the potential to avalanche in stability tests. 

The new snow last night fell onto weak surface snow, came in with wind and with a rise in temperature.  Storm slabs may be easy to trigger even at lower elevations. Investigate whether the new snow is bonding to the old snow surfaces. Pay attention to cracking and collapsing. 

Watch for glide cracks and remember to limit time under these, there have been a handful that released last week. *Several cracks have been opening in popular terrain like Tincan’s Common bowl and the SW face of Sunburst. These may be hard to see with new snow.