Aspect: All

Elevation: Above Tree Line

Bottom Line: As we transition into springtime, be aware that conditions within the snowpack can change rapidly. Last weekend produced 4-10” of snow over several days in the alpine. This week has beckoned in warmer days and colder nights which has created temperature fluctuations at the surface of the snowpack called diurnal recrystallization. As this process weakens the snow at the surface, it may be possible to trigger unconsolidated pockets of loose snow within the surface layer. At the point of the release the snow begins to gather speed and can pick up more snow as it moves downhill creating a fan shape. Do not underestimate loose snow avalanches, especially in areas of high consequence terrain. This weakened snow also has the potential to become a problematic layer after the next storm cycle delivers new snow.

Travel Advice:

• Avoid terrain traps where avalanche debris can concentrate.
• Avoid narrow areas, where it may be difficult to escape off to the side.
• Avoid exposure above cliffs where small avalanches can create greater consequences.
• Avoid being in the run out zone of steep terrain as the fan shape can spread out over a large area.
• Avoid long, sustained slopes as the potential for more snow to gather can increase the hazard.

Additional Consideration:

We believe deeper persistent layers are currently dormant. However, you could still trigger a persistent slab in thin or shallow snow even if we haven’t had recent feedback or avalanche activity. With the beginning of March comes a higher sun angle than we have seen for the last couple months. Surface warming will begin to be prevalent on solar days, especially around exposed rocks and creating thin and/or weak spots where you could trigger these deeper layers. Remember that persistent slabs are unpredictable and that tests and observations can be unreliable. A probe can be very helpful to determine snow depth and presence of deeper buried weak layers by noting resistance as the probe moves through the snow. Continue to use wide margins of safety, collect information and be patient when it comes to more committing terrain.