Northern San Juan

A handful of small natural avalanches observed in the recent snow.

The minimum temperature at Putney weather station (12327) was -7 degrees and a maximum of 10 degrees. Clear skies and sunshine made temperatures feel warmer that recorded. Moderate northwest and west winds were 10-15 mph while we were out. The storm total from Friday to end of the day Saturday at Red Mountain Pass totaled 21 inches at 1.25 SWE. Wind effect on Sunday made measurements of additional snow difficult, but around 2.5 inches at .15 SWE were picked up. The winds between 11am Sunday and 11am today (the 24 hours with the highest winds), averaged 25.1 mph from the northwest with a peak gust of 64 mph at the Putney weather station (photo of wind rose included).

The thickest slabs of stiffened snow were adjacent to ridgeline on east and northeast slopes and over 3 feet thick, but did not extend far below the ridge. Isolated pockets of slab near treeline were about 1.5-2 feet thick. While some of these slabs may be sitting on areas that were barren and rocky (due to the high winds gouging surfaces on the 17th), it's a better bet that these slabs are sitting on firm wind-pressed surfaces or weak facets. This means that we have the structure for a Persistent Slab avalanche problem most places you find stiffened slab conditions in the new snow.