Observation Date: 04/24/2020
Route/Location:
We skied the traverse starting at the main Rattlesnake corridor trailhead and finishing at Snowbowl skiing the north facing aspects of Stuart, Eagle Chute and Mosquito before crossing Grant Creek basin to Point 6.
Weather:
Warm and sunny
Wind:
Low to moderate depending on location. Higher winds on exposed points like summits. Lots of evidence of wind effect including large cornices, waves and pillows on most aspects. Only true north faces with a feature like a ridge to block the wind were unaffected.
New Snow: No New Snow
Avalanche Activity:
We encountered a variety of instabilities: reactive wind slabs about 6 inches deep, wet loose on sun affected aspects, dry loose on north aspects and even a large glide crack opening up on the SE side of Mosquito. In areas with no wind of sun affect, we had no failures in our tests with sluffing being the only problem we encountered. We saw one large windslab that released down one of the Mosquito Peak chutes about 6 inches deep that ran the whole length. Most chutes on Mosquito were heavily wind slabbed with the exception of the one we skied at a slight aspect change and protected by rock walls. Saw a party cutting off good sized wet loose slides from burgundy ridge late in the afternoon.
Other Comments:
The day required careful navigation and assessment as conditions were hyper local to elevation and aspect and changing quickly with time throughout the day. Skiing quality ranged from fantastic mid winter powder skiing to survival breakable crust or mashed potato flailing. We were not able to find the bottom of the snowpack with a 240cm probe on a northern aspect near the summit of Stuart Peak but expect melt and avalanche activity to increase with warmer temps in the coming week.
Observer: Miles K.