Professional Observation

Observation Details

Signs of Unstable Snow

Snow Stability

Key Points

• Raking northeasterly winds were visibly stripping snow off the highest peaks and further eroding alpine northerly and easterly aspects.
• Chilly day with temperatures in the teens to 20sF. 20degF @ 9000ft @ 230pm
• Fairly calm conditions in lower Lee Vining Canyon until I reached 9000ft where the northerly breeze was blowing.
• Robust well-developed large surface hoar upwards of 1-1.5cm in size in moist creek bottoms and along the Lee Vining creek. Did not observe surface hoar beyond these moister environments.
• Thin temperature crusts up to 8500ft that are degrading and easily skied through.
• A majority of travel through northerly terrain within the forest found 5-15cm ski penetration on near surface faceted snow.
• Boot Penetration at 9300ft was 25cm on due north aspect.
• Snowpit at 933oft found 90cm of rounding solid snow pack. NO RESULT on column tests or Extended column tests. 10cm of Fist hardness near-surface facets on the surface above a a top-down progressively firm pack Finger-Pencil hardness with no faceted snow at base of snowpack here.
• NO instability what so ever.