Red flags, east side, 4000-4200’ elev.

By Ryan Matz | MWAC

Date of Observation: December 7, 2018  11:00 AM
Location of Observation:

Shooting cracks in the areas of rapidly developing wind slab.
Hand shears failing on isolation with Q1 shear quality (clean shear).
Newest/top layer of wind deposited snow, likely formed early this morning (12/7), was the reactive layer, appearing to fail on the interface with older snow. This layer varied from ~5-50 cm and has continued to build since on increasing wind speeds.
Snow fallen since the Sunday/Monday melt/freeze has been transported by predominantly W and NW wind, especially today. Refrozen crust is either under this new snow, which has built into thick wind slabs in places, or at the surface depending on exposure to recent and continuing wind.


Snowpack observations are one part of the complex puzzle which is your decision to enter avalanche terrain. Some observations may include stability tests. It’s important to understand that the results of a stability tests are seldom conclusive anywhere, but particularly in snow climates and terrain like ours where the primary driver of instabilities is wind drifted snow. Many stability tests exist and each works best with specific avalanche problem types. Stability test results should never be used alone as an indication that a slope or conditions are safe particularly when more obvious red flags are present. Please use this page as part of your information gathering process, but don’t make decisions based on a single piece of information. A good article that summarizes some of the issues associated with snow and avalanche observations can be found here.

The Mount Washington Avalanche Center cannot verify the quality or accuracy of any observations that come from the general public.


See an avalanche or evidence of previous avalanche activity?  Near-miss? Snowpack observations?

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