Selkirk Mountains

Near and above the treeline, the combination of fresh snow and elevated winds is forming shallow slabs above the old, saturated now refrozen snow surface. While these slabs are generally shallow, they have been easy to trigger recently. As snowfall adds up or in places where the wind has built deeper drifted slabs, below ridges and in gullies, their sensitivity and size is likely to increase and have a better chance to catch you off guard. Now that the region has returned to cooler weather conditions, wet snow hazards have likely locked up, and only pose a very isolated threat.

Springtime can offer a great opportunity to travel around the mountains with a bit less fear, and allow us to step into terrain that is typically off-limits during most of the winter. One part of spring that often doesn’t happen in the winter is the dramatic minute-by-minute to hourly weather swings - one moment it’s sunny and hot, and you're sweating profusely. Then the next, it’s cold and snowing, and you’re having to put on a layer. These wild fluctuations require us to manage both dry and wet avalanche problems that can evolve much quicker than we anticipate - primary drivers being how long the sun is out or how long it snows. Just because you encounter tricky or muddy trailhead logistics, or you see budding flowers and green grass in the valley’s, you still need to be thinking about avalanche hazards in the mountains.

With the return of cooler temperatures, our Wet Slab avalanche threat will slowly lose its bite, but can hang around or come back into striking distance with little notice. The main wetting front from last week's rain and HOT temperatures that made a weak, manky mess of the upper snowpack has likely traveled deeper or to the ground. Places where water got hung up will likely refreeze during long periods of below freezing temperatures and lock up those instabilities. However, as we flip the calendar closer to April, the sun angle gets higher in the sky and this can have a profound influence on reemerging wet snow hazards - even thawing refrozen meltwater closer to the surface. Be wary of slopes with large glide cracks as the amount of water moving through the system could nudge these slopes closer to failure as the barrier between the ground and the entire snowpack gets lubricated like a slip-n-slide track. Glide avalanches are unpredictable at best to forecast.

The dueling battle of warm versus cold air enhanced by orographic lift when storms move through can lead to intense periods of snowfall, and rapid accumulations. Depending on the type of older snow surface the new snow falls on will have a big influence on bonding and how sensitive fresh slabs are. Use surface clues of unstable snow and non-consequential test slopes to set yourself up for success and identify areas of slopes to simply go around. Stepping into more complex or extreme terrain still requires cautious snowpack assessments and decision-making where even a small, more isolated slide can lead to a bad outcome.

Lastly, fresh snow can be like adding another glass of water to the saturated ground, and it doesn't take much new snow warming under sunny skies to increase the chances to trigger a wet avalanche. More new snow often equals larger wet snow slide potential. Frequently assess surface wetting as you move up and down in elevation as you will likely not find conditions to be the same down in the mature timber as higher up, and vice versa. Now is a great time to take advantage of longer days and get out on longer tours or rides. Consider exiting the mountains early if conditions change faster than you anticipate, or you start seeing fresh evidence of natural activity.

**Eastern Oregon University is conducting a survey to better understand avalanche safety preparedness among motorized backcountry users. The survey will help us learn more about who is purchasing, and practicing with avalanche rescue gear (beacon, probe, shovel) and participating in avalanche education—and why some riders are not. The survey is confidential and anonymous. Your feedback is invaluable to improve avalanche education and awareness across North Idaho and Northwestern Montana. Please take a moment to share your experience and help your local avalanche community. You can take the survey HERE.**