North winds will increase through the day today, becoming strong with gust up to 50 mph expected along high elevation ridge lines.  There is currently a lot of loose snow available for transport.  This will quickly be forming fresh wind slabs and adding to the depth of slabs created on 3/24.  Wind slabs that form today are expected to be reactive to human triggers 1-2 feet in depth.

On 3/24 south winds were moderate to strong in exposed terrain.  Wind slabs were building quickly with signs of instability such as shooting cracks present.  Expect to find wind slabs on a variety of aspects today as winds switch to the north and increase in strength.  

Wind slabs will have the potential to step down to deeper layers in the snowpack and create large, destructive avalanches (see problem 2)

 Wind slabs that build today will be adding stress to the 2-3 feet of snow delivered by the Hamilton storm (3/17).  Wind slabs may be able to step down to some of these deeper layers.  Strong wind affected snow still exists at the 3/17 interface, although has been observed to be breaking down at mid elevation in some locations.  This will increase the potential for a person or machines weight to stress deeper layers in our snowpack.  

In areas that were more protected from late February-early March north winds, the 3/17 interface consists of near surface facets.  This difference in interface is important to identify.

 Human triggered avalanches are possible up to 4 feet deep in areas where facets are present at the 3/17  interface or where the Hamilton slab is deeper than 3 feet.  These conditions are not as likely to be found within our forecast zone but have been reported in areas to the southeast of Thompson Pass that received higher storm totals, and in more continental locations where the underlying snowpack is weaker.  Use caution in steep terrain that is being actively loaded by wind.

 Ski pole probing and digging snowpits are good ways to identify what type of interface the recent new snow is sitting on.  The 3/17 interface continues to be a low friction potential bed surface.  There is uncertainty if this will become an issue as we receive more snowfall and/or heat is able to heat penetrates further into the snowpack in the future.

Other persistent weak layers exist in our mid to lower snowpack.  These are currently unlikely to be affected where very strong wind affected snow exists at the 3/17 interface.

Wet loose avalanche activity is expected to be limited today as strong winds will likely keep slopes cold.  The one exception may be on low elevation south aspects of the Maritime zone.  Wet loose avalanches that may occur today are expected to be small in size.  Avoid steep terrain where the surface snow is becoming moist to wet during the heat of the day

Weak snow exists at the base of our snowpack.  This weak snow is currently unlikely to be affected due to the strength of old wind affected snow at the 3/17 new/old interface.  Depth hoar may become a concern later in the season if our area continues to see major snowfall and the very strong wind damaged layer at the new/old interface starts to break down and lose strength within the snowpack.  As very hard wind slabs break down within the snowpack a person or machines weight will have a more direct affect on weak layers at the bottom of the snowpack.  In addition,  the increasing intensity of the sun will be putting pressure on deep layers during the heat of the day.