Maritime

Avalanche problems

• 

  Loose Wet

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Possible

  Size

  1–2

  Wet Loose (Maritime): Rain on snow at lower elevations will create potential for wet loose avalanches in steep terrain. The surface snow is already saturated, so we do not expect the sharp spike in reactivity that often occurs when dry snow first sees above-freezing temperatures or the first pulse of rain. That said, wet loose activity remains possible today, especially on steep slopes where saturated snow can peel away and run farther than expected.

  Avoid travelling in steep, consequential terrain at low elevations in the Maritime zone today.  Avoid terrain traps such as gullies and creek beds where even a small wet loose avalanche could pile up deeply.

  Storm snow (Maritime): Expect new snow to accumulate above 1500’ in the Maritime zone. Pay attention to how much new snow is building and how reactive it feels. Watch for signs of drifting (pillows, textured snow, cracking). Quick assessment tools like hand pits and small test slopes work well for determining how sensitive storm slabs are in the terrain you’re traveling through.

  

• 

  Deep Persistent Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Unlikely

  Size

  2–3

  Weak snow near the ground exists at all elevations and is now deeply buried in most locations. In many areas, basal facets are bridged by stronger, stiffer layers in the middle of the snowpack. As this problem gets deeper it becomes harder to trigger and is unlikely to produce obvious red flags like cracking or collapsing. Expect a stubborn, unreactive deep slab in most places—this is a low-likelihood / high-consequence setup.

  The most likely trigger points are thin spots, especially steep, rocky terrain where the weak layers are closer to the surface. A rider may be able to stress the basal weak snow in these shallow areas, and a small trigger could step down or propagate into deeper, thicker parts of the snowpack, producing a large and destructive avalanche. The best way to manage this problem is to avoid steep, rocky features and other shallow-snow areas where the snowpack is thin and variable.

  In the Continental zone, the hazard will remain CONSIDERABLE where the snowpack is thinner, weaker, and more easily affected by human triggers. Human-triggered deep slab avalanches are possible in the Continental zone. They are unlikely in other zones, but if triggered could produce very large avalanches with a very low chance of survival.