GOS Gully #1

By Helon Hoffer | Mount Washington Avalanche Center

Date of Observation: December 6, 2018  10:30 AM
Location of Observation: Gully #1, Gulf of Slides

What follows is a description of the snowpack found in Gully #1, starting in the snowpack at the Melt/Freeze crust that was supportable everywhere except in the bushes.
+The MF crust has a layer of decomposing graupel on top of it. This was found at all locations and is Fist hard.
+On top of the graupel was a layer of 4F wind slab. This varied from 20cm thick on climber’s right side to 4cm thick on climber’s left side.
+On top of the 4F wind slab was pencil hard wind slab that likely formed on December 4. This varied from 4cm thick on climbers right to 15cm thick on climbers left.
+the surface of the snowpack was 5cm of very light density snow.
Compression Test results varied, with scores ranging from CT15 to CT21.
Propagation Saw Tests scored PST90.

Upon reaching the rollover high in the gully, wind picked up and a reactive slab was beginning to form.


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.


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