The hazard is forecasted to be similar to yesterday. Instabilities that exist, will be near the surface.  Stable conditions have been reported and observed in most locations.  The exception to this will be in the Maritime climate zone at low elevations (see problem 1).  Human triggered storm snow avalanches are possible 1-2 feet in depth.  Our area is expecting 3-5 inches of snow today with light to moderate southeast  winds that will eventually switch to west.  This amount of new snow is not expected to increase the hazard above moderate.  If more than 8 inches of snow accumulates the hazard would move to Considerable.

Several small storms have traversed our area over the last week depositing up to 2 feet of new snow near the coast with less than a foot on Thompson Pass and north.  Several interfaces between these storms exist that are sensitive due to continued snowfall despite the one day of blue skies on the 15th.  The good news is that in the majority of locations, the surface snow is uncohesive (no slab) and stable conditions have been observed and reported.  The concerning thing is the amount of loose snow that exists.  Where surface snow is stiffened by wind, a slab will exist and the likelihood of triggering an avalanche will increase.

 Stability above 2500′ will directly correlate with the presence and depth of wind slabs at the surface.

The main concern today exists in the low elevations of the Maritime climate zone.  Human triggered avalanches are possible up to 3 feet in depth below 2500′.  A rain crust created on 1/25 has formed a potentially dangerous persistent weak layer in the Maritime  zone below 2500′, this includes Keystone Canyon.  This layer has been identified on Thompson Pass and north although, has been found to be much less of a concern in those areas.  The possibility of human triggered avalanches can’t be ruled out in steep and/or unsupported terrain north of Thompson Pass.

On 2/16 this rain crust was found to have signs of instability at 1800′ just east of Benzene Alley (Port of Valdez).  These include one very large collapse and propagation present in both ECT‘s and PST‘s repeated multiple times 3 feet down (see observation page).  The depth of this layer will make it difficult to trigger in most locations, but the consequences would be high due to the depth of the slab.  This weak layer was previously found to be faceting creating an area of poor structure, although only recently has propagation popped up in stability tests.  This may indicate that the amount of snow we have received near the coast may be pushing this weak layer towards the tipping point.  Careful assesment of this layer is advised especially if traveling in steep and/or unsupported terrain below 2500′ in the maritime climate zone. 

Watch for signs of instability such as shooting cracks and collapsing.  Digging snowpits to assess stability in the area you choose to travel is a good idea if choosing to travel in steep terrain at low elevations in the Maritime climate zone.

Weak snow continues to exist near the base of our snowpack in all three climate zones.    The last recorded avalanche activity at this layer occurred during the 1/23-25 storm on Nicks Buttress / ~3500’/ north aspect (see avalanche activity section).    This layer is believed to be dormant as there has not been deep avalanche activity for 3 weeks, and only 2 observed in 2 months.   Human triggered avalanches are currently unlikely to occur that fail on weak snow near the base of our snowpack.

Faceted snow near the ground has been found to vary significantly from place to place.  In most locations this snow has been found to be rounding (gaining strength) and unreactive in stability tests.  In thin areas of the snowpack these facets are significantly more developed.  Unlikely does not mean impossible,  if a person were to affect weak snow near the ground it would be in areas where the snowpack is thin.

If you find it is possible to push a ski pole to the ground in areas you travel.  Assume that a weak faceted snowpack exists in that location, that could act as a trigger point.  An example of the difference in faceted snow that has been recently found can be seen below.

Depth hoar from Nicks Buttress ~4000′ North aspect 1/31. This was from an area where the snowpack 3 feet deep.

Rounding depth hoar on Cracked Ice / north aspect/ 3000′  on 2/11.  This was from an area where the snowpack was 7 feet deep