Seward and Lost Lake

Avalanche problems

• 

  Persistent Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Likely

  Size

  2–3

  Recent avalanches: The last known avalanche activity in the Seward and Lost Lake zone was during and immediately after the atmospheric river event, which occurred just over a week ago, between January 16th and 19th. 

  There are numerous avalanche problems today due to active weather and a well-documented persistent weak layer buried deeper in the snowpack. If you're still keen on recreating in the backcountry, you'll likely be spending the majority of your time in the 1,000 to 2,500' elevation band today.  This is where you'll find the best visibility and surface conditions.  Unfortunately, this is also where we're finding the persistent weak layer (crust/facet combo) still very much intact and producing unstable results in our snowpits as recently as yesterday.   Currently buried ~2-5' deep, this layer is becoming more difficult for a skier or snowmachiner to trigger. It is unlikely to give us any feedback we yearn for, such as shooting cracks or big whumpfs, before avalanching.  The slab is deep enough now that if a skier or rider were to initiate an avalanche on this buried weak layer, it would be catastrophic.  Trigger points, such as small trees or rocks breaking the snow surface, are the areas most likely to trigger a large and dangerous avalanche.  If travelling in the mid-elevation band, cautious route-finding and conservative decision-making will be essential.

  In lower elevations, below about 1,000', the snowpack is thin, and unfortunately, we are seeing more rain today.  There is, however, enough snow in the mid and upper elevations that it's possible debris could reach below 1,000' in funnelled terrain.  

• 

  Storm Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Very Likely

  Size

  1–2

  Expect natural avalanches in the form of fresh storm slabs and wind slabs above treeline. With storm intensity expected to peak this afternoon, travel in avalanche terrain above ~2,500' is not recommended.  In the 1,500' to 2,000' elevation where the rain/ snow line is, triggering a storm slab avalanche 1-2' deep isn't out of the question.  Keep in mind that a smaller storm slab avalanche could be enough to trigger a much deeper and more dangerous persistent slab avalanche, discussed above. 

  Cornices: Cornices have been unusually small this winter in many of the usual places, but the warmer storms and active weather we've experienced in the latter half of January are definitely adding weight and instability to these backcountry bombs.  Be aware of corniced ridges, both travelling below and on top, as these tend to break much further back than expected.