The avalanche danger will rise today as snow and wind increase the size and sensitivity of new surface slabs as well as the potential to trigger deeper instabilities within the snowpack. Steep terrain with obvious signs of wind loading should be avoided as the new snow will be sensitive to skiers and riders and could release naturally this afternoon. Conservative decision making is essential during storms that produce rapid loading.
Snow that started to fall yesterday is accumulating on a variety of snow surfaces including faceted snow in shaded terrain and hard crusts formed during the recent inversion conditions. Strong southwest to west winds will form sensitive soft slabs that could have depths to 2 feet this afternoon.
A chance exists to trigger large to very large avalanches involving older layers within the snowpack. Failure could occur on a rain crust buried on Christmas, or possibly on older crusts and facets when a weak or shallow point on a slope is impacted. Larger triggers such as a cornice fall or a moving wind slab may be necessary to cause failure of these deeper layers. If initiated, avalanches involving these layers would be large and dangerous hard slabs with depths ranging anywhere from 2 to 10 feet.
(1/1/2026)
Hard slab remotely triggered by snowcat after terrain hit by large explosives in closed terrain at JHMR.
If the forecast precipitation of a foot of additional snowfall materializes today, the new soft slabs will become very sensitive this afternoon. This new slab hazard will be the more obvious hazard to navigate and will evident by deposited snow and warning signs such as shooting cracks. The deeper layers of concern include the rain crust buried on Christmas that was active in cliff bands earlier this week, the prominent rain crust that formed on December 10th, and in high, north facing terrain basal facets buried in November. The slide that occurred in the closed upper portion of JHMR yesterday known as the North Ridge exemplifies the buried problem. After large explosives did not produce avalanches, a snowcat moving a massive amount of snow in adjacent flat terrain remotely triggered a hard slab with a depth of 10 feet. It would be extremely unlikely for a single person to trigger a similar event but groups of people, snowmachines, or natural impacts such as cornice drops could cause a large avalanche in very steep, high, north facing terrain.
