Chugach State Park

Lawinenprobleme

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  Storm Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Hochgebirge
  • Waldgrenze
  • Unterhalb der Waldgrenze

  Wahrscheinlichkeit

  Very Likely

  Größe

  2–3

  Recent Avalanches: Five hikers were involved in an avalanche on Peak 3 on Saturday, including two people partially buried with injuries. There were multiple avalanches triggered remotely Wednesday evening on the back side of Seattle Ridge. We also saw the aftermath of a very significant natural avalanche cycle in the Portage Valley; check this observation for a scary description of activity in the Byron Valley and a few photos of some of the other activity in the area. There was debris from multiple large loose avalanches seen from Seward, and multiple large slab avalanches have released naturally in the Summit Lake area over the past two weeks.

  Today's storm will likely be the most intense 24-hour event we've seen all winter. As of 5 am this morning, wind speeds are already averaging 50 mph with gusts near 80 mph. Precipitation is just getting started for most areas, but weather stations closer to the coast (Portage and Seward) have already measured over 1" of precipitation in the past 12 hours.

  By the end of the day, we will likely have 1.5 to 2' new snow in Girdwood, Turnagain Pass, and Lost Lake; 3 to 5' snow in Portage and Seward; and 4 to 8" in Chugach State Park and Summit Lake. This will fall as heavy rain up to 500' to 1000'. All of this is happening on a snowpack that is wet and sloppy below treeline, and stacked with buried weak layers at and above treeline. All avalanche problems are on the menu today- storm slabs, wind slabs, persistent slabs, deep slabs, and cornice falls at and above treeline; wet loose and wet slabs below treeline; and maybe even a dry loose avalanche somewhere in the mid or upper elevations.

  The snowpack will get pushed to its breaking point today. Natural avalanches are expected. Some of these will run long distances into low-elevation runout zones. Travel in avalanche terrain is NOT recommended.

  

• 

  Persistent Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Hochgebirge
  • Waldgrenze
  • Unterhalb der Waldgrenze

  Wahrscheinlichkeit

  Likely

  Größe

  2.5–3.5

  There are several buried weak layers throughout the snowpack that will be heavily stressed today. These weak layers may produce avalanches anywhere from 2' deep to over 6' deep, and the size and likelihood will increase as the storm continues. Avalanches may propagate across wide distances and run far into lower elevations. 

  This heavy load on top of a problematic snowpack will remain a concern even after the storm passes. This combination of a major storm event on a weak snowpack is capable of producing very large, unsurvivable avalanches. For now we're not going anywhere near avalanche terrain.