Bitterroot

Cold temperatures and cloud cover will keep the snowpack locked together. Apart from an isolated pocket of wind drifted snow on east aspects at our uppermost elevations, slips and falls on icy surfaces or breaking through thin snow bridges over creek crossings are more of a hazard than avalanches today. Continue to look for any signs of snow instability, like shooting cracks or sinking past mid-boot in wet snow, and evaluate snow and weather conditions as you travel. 

We finally got a refreeze the past two nights. We can thank the colder temperatures from a small low-pressure system and clear skies Tuesday night for this. A solid refreeze last night and freezing levels hovering near 6,000 feet throughout the day should keep most everything well bonded. Before this freeze, our snowpack was isothermic saturated mush with free water throughout in most areas. We had over a week of elevated temperatures and limited nightly refreezes. We lost a lot of snow. Elevations below 6,000 feet are at the point where avalanches have become unlikely simply because there isn’t enough snow in most places. 

If temperatures warm higher than forecasted, the refrozen crusts at the top of the snowpack may begin to break down and lose cohesion. If this happens, the possibility of triggering a loose wet avalanche will increase. Watch for moving wet snow like pinwheels and rollerballs as signs of wet loose avalanche potential. Pick shadier aspects or exit avalanche terrain if you’re sinking past mid-boot in wet snow.

Yesterday we found an 8-inch supportable crust in the Rattlesnake at 7,800 feet. Similar supportable crusts were reported from the Bitterroot. Cloudy skies and moderate gusts kept the snow surfaces firm and supportable. Avalanche danger was low.

The temperatures dropped into the low to mid-20s for elevations above approximately 5,000 feet around 1 am yesterday morning. Lolo Pass at 5,240 feet has had 12 hours of below-freezing temperatures in the past 24 hours. Afternoon temperatures reached 43 at 7,940 feet on Saddle Mountain in the southern Bitterroot but only reached a high of 36 on Stewart Mountain at 7,400 feet in the Rattlesnake. 

Over the past 48 hours, the light snow showers might have brought enough fresh snow for the wind to create a small slab and our uppermost elevations. The majority of the moisture fell as rain below approximately 8,000 feet. Up to 4 inches of fresh snow and 1 foot deep drifts were observed in the Bitterroot yesterday. Up to 2 inches is forecasted today with light westerly winds and moderate gusts.

 If you find fresh snow, look for smooth and rounded wind deposits and shooting cracks as signs of nearby wind slabs. These would be small and isolated but could be enough to knock you off your feet, over a cliff, or a shallow burial in a terrain trap. Large cornices loom over eastern ridgelines. The colder conditions today should keep them locked in place, but it’s still possible that they could break unexpectedly. They deserve respect, and it’s best to avoid traveling near the top edge or directly below them.

Ski and ride safe.