Backcountry Avalanche Forecast for Southern San Juan 	
Issued: 02/02/2013 7:06 AM by Matt Steen

Highlights

Temperatures remained mild yesterday and did not warm up as quickly as on Thursday. Today's early 
morning temperatures are already at Thursday's high marks, ranging in the upper teens and lower 
twenties above treeline. Today, direct sun and warming temperatures can trigger loose snow 
avalanches on southerly facing terrain near and above treeline. Persistent slabs and wind slabs 
remain as avalanche problems elsewhere. Today's warm and dry weather will continue to settle the 
snowpack. The avalanche danger is easing with mild temperatures, but triggering an avalanche 
remains possible.

Avalanche Danger

The avalanche danger for the Southern San Juan zone is MODERATE (Level 2) on all aspects and 
elevations. Heightened avalanche conditions. Evaluate snow and terrain carefully; identify 
features of concern.

Snow & Avalanche Discussion

Mild-dry weather since Thursday continues to settle the snowpack. This settled snowpack is 
transitioning into a cohesive persistent slab. These persistent slabs are sitting on a variety 
of snow interfaces and snow depths. These include buried surface hoar, faceted snow near the 
ground and deeper persistent slabs. If you trigger a small avalanche, it can step down into 
deeper weak layers. It may be getting harder to trigger an avalanche, but if you do it could 
step down to deeper weak layers, and pull out a much larger deep persistent slab avalanche, 
and run to the ground.

Moderate winds blew during last week's storm. Southwest winds veered northwest through the week, 
which built thick wind slabs and drifted snow behind terrain features and cross-loaded gullies 
near and above treeline. If you are traveling in near and above treeline terrain today, the 
primary avalanche problem will be these wind slabs. Slopes that face northeast through southeast 
to south will be most sensitive to human triggers. These slabs can range in thickness, and will 
be most easily triggered from the side, bottom or where the slab is thinnest. If you trigger a 
stiff, cohesive slab avalanche, it will likely be large and destructive.

Continued warm temperatures and direct sun will loosen snow on steep southerly aspects above 
treeline. Roller balls and wet gloppy snow can easily trigger point-release, loose-dry to 
loose-wet avalanches. These slides start small, but can quickly entrain more snow, becoming very 
large.

There are heightened avalanche conditions today. Evaluate snow and terrain carefully.