Salt River and Wyoming Ranges

Expect continued avalanche activity due to even warmer conditions today.  Natural and human-triggered avalanches will become likely this morning as sunshine warms slopes, especially gullies and rocky bowls. Move to shady aspects when steep snow surfaces become sloppy and wet.

For whatever reason, North American avalanche professionals, most of whom have lots of post-graduate education and experience, decided on the current avalanche problem types that we use in public backcountry forecasting. Consistent use of these problems allows for coherent curriculum in avalanche classes and messaging in bulletins like this one. The line between these problem types gets blurry and the technical details of each are many. When the snowpack heats up for the first time in the spring (or late winter as it happens to be now), it's best not to get too hung up on the esoteric nuances of the problem types. That can wait for a discussion at the bar, or deep in the avalanche forecast. We've been messaging on two problems with definitions that are nuanced, but that matter only in the bigger picture. Our current wind slab problem is currently complicated by the presence of some weak snow grains. If these layers of near-surface facets or crust/facets were distributed more widely, we'd use the Persistent Slab avalanche problem because the problem location and hazard mitigation considerations would fit better than the advice associated with wind slabs. We've seen the weak layers propagate in wind-loaded areas so the travel advice and messaging fits better with the Wind Slab problem type. Rather than ring the alarm for widespread and long lasting Persistent Slab problems, we chose the wind slab bucket. 

On a related note, we are not messaging about wet slabs yet for two reasons. The first reason is that Wet Slabs will carry a much more serious consequence involving wider propagation with avalanches running much further and deeper than what we are seeing currently. Secondly, wet slabs have very specific definitions laid out by the aforementioned cabal of avalanche professionals. Those tell-tale characteristics include saturated snow down to a weak layer, a gouged avalanche path due to the mass of the debris, 32F snow temps down to the weak layer, little if any dry snow involved in the avalanche and with weakening snow structure deep in the snowpack. All of those characteristics will take multiple nights of above-freezing temperatures to become a reality.  When we get there, it will be great to have the problem type and distribution to clarify what will likely be a more widespread problem with lower frequency (probably) and bigger and even more dangerous avalanches. The avalanche problem types don't always work with the old duck analogy...if it walks like a duck and quacks like a duck, it's a duck. In these cases, we have western grebes walking funny and making quacking sounds with their beaks.  

Reminder that closed ski areas are reverting to wild snow conditions and natural avalanches large enough to bury a person can occur there.  Warmth and sunshine can cause avalanche problems, even on previously groomed and heavily compacted slopes. Read the forecast but remember that the snowpack will be different at closed ski areas. 

If you see avalanche activity today, please consider submitting an observation HERE. Observations allow everyone to gain a better and more complete understanding of conditions. Thanks!