Southeast Mountains

Numerous natural avalanches failed this past week in the Southeast Mountains due to wind-loading on a wide variety of aspects.  You are more likely to trigger a dangerous avalanche from a shallow spot on slope where slabs become thinner.  Features with highly variable snow depths due to rocky terrain or wind effect should increase your suspicion.  Do not expect signs of instability to warn you and do not allow previous tracks to trick you into thinking a given slope will not avalanche.

Both forecast zones, Northwest and Southeast, are sitting at MODERATE at all elevations.  The area is well over a week out from the last storm event, but bouts of wind over the past week have allowed a trickle of natural avalanches to continue (see media gallery below).  It appears as though the string of isolated natural avalanches has ended.  This leaves human-triggered avalanches as the concern.  The snowpack is entering a low probability yet high consequence period meaning that the chances of you triggering an avalanche are decreasing, but the expected avalanche size remains just as large and dangerous if you do find that trigger point.  Just look at the reported avalanches from this past week to see the difficulty in surviving one of these nasty avalanches.  Do not doubt the widespread nature of basal weak layers and the dense slabs resting above.  The ugly structure is widespread but knowing which spots on any slope will produce a deadly avalanche is the challenging part.  Consider the unique and dangerous nature of the snowpack this winter and continue to expect the unexpected.

If you are looking to venture out into avalanche terrain consider terrain shape and uniformity of the snowpack.  Smaller slopes, that are free from shallow areas like rocks, cliff bands, or wind effects offer less likely places to trigger a dangerous avalanche.  It is important to remember that not all trigger points can be visually seen from the surface.  Sometimes trigger points are hidden under the snow and are imperceptible to the eye.  Sometimes it's the 3rd, 8th, or 11th person on a slope that finds a trigger point or maybe your 4th highmark on a snowmachine before you release the entire season's snowpack down.   Take a look at photos in this observation from upper Cement Creek (Southeast Mountains) to see terrain that has a highly variable snowpack where you have a better chance of finding a thin portion of the slab, or trigger point, and could bring down the house of cards.  Highly variable snow depths are more common in the Southeast Mountains, but there are plenty of locations in the Northwest Mountains that look similarly untrustworthy, for example, look at this observation from control work at Irwin on westerly near treeline slopes.  Take a look at this video from Zach Guy for more information about trigger points and variable snow depths.

Risk tolerance is a group decision.  If your group is intolerant of triggering a dangerous avalanche then choose simple, lower-angled, and shorter slopes that offer reduced consequences.  The 'magic bullet' will be terrain less than 30 degrees that are not below or connected to steeper slopes.  The opportunity to venture into bigger alpine terrain with a larger margin of avalanche safety will come later this spring as it always does.