Northern San Juan

Snowpack

Bill Nalli · Jan 27, 2020 · Northern San Juan

Weather

Snowfall accumulated earlier than expected and by 1 pm 6" of low density snow had fallen. Wind was light for the first part of the storm and then picked up in early afternoon into the 20's with gusts in the 30's. First from the northwest and then from the north. By evening speeds had increased to 30's gusting into the 40's.

Snowpack

Conditions changed quickly once about 6 inches had accumulated. Generally poor bonding with the old snow surface caused the first 5 to 6 inches to sluff on slopes steeper than 38 degrees. As new snow depths increased to 6 to 8 inches, and strong northwest and later north winds began to blow, soft slabs began to form. These were easy to initiate in very steep terrain and travelled far downhill until the slope transitioned to lower angle.