Seward and Lost Lake

Lawinenprobleme

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  Storm Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Hochgebirge
  • Waldgrenze
  • Unterhalb der Waldgrenze

  Wahrscheinlichkeit

  Likely

  Größe

  1–2

  With 1 to 2’ of snow falling since Saturday we get another chance to enjoy soft snow and a little winter weather. That being said, avalanche conditions are dangerous and it will be easy to trigger a large avalanche up to 2’ deep in the storm snow. This is a lot of snow adding stress to a snowpack that is already unstable. Triggering a storm slab avalanche may step down to a weak layer that could trigger a large wet slab or persistent slab avalanche. The safest option is to stick to lower angle terrain away from steep overhead slopes and avalanche runouts.  

  Another 4 to 6” of heavy snow may fall today on top of lighter snow as the snow line is expected to increase to around 800’. This will mean that heavier snow will fall on top of lighter snow making it easier to trigger an avalanche in the new snow. Moderate winds yesterday have also moved snow into wind slabs that could be 3' deep or deeper. Recent avalanches, shooting cracks, collapsing snow and traveling on stiffer snow over softer snow are all clues that you may be on a slope that is ready to slide.  Due to the possibility of triggering a large avalanche in the new snow which may trigger a deeper avalanche the safest option is to ride lower angle terrain that is not below steep slopes or in avalanche runouts. 

  Storm totals below are from 12 AM Friday morning through 6 am this morning:

  • Portage: 10.5" Snow Water Equivalent (SWE), equaling 6 to 8' snow above treeline. 
  • Girdwood: 4.8" SWE equaling 2 to 3.5' snow. 
  • Turnagain Pass: 2.9" SWE equaling 12-24" snow.
  • Summit Lake: 0.6" SWE equaling 3-6" snow.
  • Seward/Lost Lake: 2.5" SWE equaling 16-24" snow

  Cornice Fall: Stormy weather has pushed cornices to their breaking point. These may release naturally, possibly triggering a large avalanche above you. Avoid spending time under cornices and give them a lot of room if you are traveling on ridges.

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  Wet Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Hochgebirge
  • Waldgrenze
  • Unterhalb der Waldgrenze

  Wahrscheinlichkeit

  Likely

  Größe

  2–3

  Over the past 4 days rain and snow has added an immense amount of stress to the snowpack that is already unstable. We know this because there have been many wet slab avalanches and glide avalanches releasing across the peninsula. Rain and warm temperatures have allowed liquid water to move into the snow where it tends to run along and melt weak layers resulting in large wet avalanches. In places where more snow or rain has fallen like near Seward, wet avalanches will be more likely. The safest option is to avoid traveling on or below steep slopes including avalanche runouts.  

  Wet avalanches including wet slab, wet loose and glide avalanches is our biggest concern. These could be on any aspect and release naturally running to valley bottoms. There are two glide cracks above Mt. Marathon that would run across the Jeep Trail and into Lowell Canyon that we are concerned about releasing. It is hard to predict when these glide cracks will release but the addition of snow and rain from this storm could increase the rate of these avalanches. If the sun comes out solar slopes may heat up increasing the likelihood of triggering wet loose avalanches. They may be larger and run further than expected.

• 

  Persistent Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Hochgebirge
  • Waldgrenze
  • Unterhalb der Waldgrenze

  Wahrscheinlichkeit

  Likely

  Größe

  2–3

  The added weight of rain and snow is adding a lot of stress on weak layers, specifically the 2/14 buried surface hoar layer. This is around 1 to 3’ deep but may be deeper. We are not entirely sure how much snow and rain has fallen in the mountains around Seward and Lost Lake which should warrant extra caution if you get out today.  

  This problem will be more concerning at mid elevations where liquid water is melting this layer and in upper elevations where snow has piled on top of it. This has been an extremely difficult layer to assess that has been responsible for many human triggered avalanches in Turnagain Pass. It goes without saying, the safest option is to avoid traveling on or below steep slopes and away from avalanche runouts.