Northern San Juan

Avalanche

Bill Nalli · Feb 8, 2020 · Northern San Juan

Weather

Stong SW wind by late morning continued throughout the day. Wind was erratic in that it was strong on one peak and non-existent on the next neighboring peak.

Snowpack

Settled storm snow varies from 30 to 50 cm deep. Below treeline is gaining strength where the snowpack is greater than 150 cm. Less than that and the whole pack is rotten and weak. The old snow surface prior to Feb. 4 was NSFC and they are now preserved below 30 to 50 cm of settled new snow. Above treeline sporadic winds are dictating where the snow is getting blown and where the current hazard is. Recent northwest and now southwest wind is creating drifts on north through east to south facing slopes. Southeast aspects lie in the center of this zone and are getting loaded from each wind direction as noted in the pic below. Slab avalanches on SE aspects on Feb 7 from NW wind direction and then again on Feb 8 with SW winds.

Avalanche

A significant but medium sized natural avalanche cycle occurred on east, southeast and south-facing slopes on Friday February 7. Naturals were centered around the Red Mt. Pass area and the zones immediately to the east and west. Slides were seen on many different aspects and at all elevations.