Forecaster Observation - Blaine Mountain, Swan Range

Traveled to the Swan Range with the focus of determining recent new snow amount, moisture content of the surface snow and state of the March 15 rain crust.

• Rode into the Blaine Mountain area on top of a supportable crust at low and mid elevations during the morning hours.
• At upper elevations no surface crust existed due to the recent snow which varied between 14-16" thick. This snow was generally 4F hard and dry as of 11:00. Intense solar input quickly warmed and moistened the surface of the new snow as the day progressed. Rollerballs and loose wet avalanche activity was observed before the clouds moved in for the remainder of the time we spent in the alpine.
• The new snow sat on top of the mid March rain crust which varied between 4-6" thick and Pencil to Knife hard.
• We dug our pits on a northeast and southeast aspect at approximately 7000'. The northerly pit had a snow depth of 320 cm with the southerly pit 250 cm in depth.
• Stability test results showed failure with hard force on top of the crust. CT 23 x 3. Failure was also observed directly below the crust with hard force. CT 28 x 3. No propagation was observed in our tests.
• We observed one relatively recent wind slab avalanche which was likely triggered by a cornice fall (large blocks of snow were observed in the debris field). This avalanche occurred on an easterly aspect at 7200'. Depth of the wind slab was estimated at 3+ feet at it's deepest spot.