Avalanche Forecast

You may trigger a storm slab on any open slope greater than 35 degrees. Potential avalanches could be larger and harder to avoid as you ascend in elevation to areas where a significant wind event Tuesday drifted slabs deeper. Storm snow will accumulate above a thin but firm crust layer formed over the MLK holiday. So far, observations indicate the new snow is bonding well to the crust, but not enough snow piled up to truly test this potential interface. That could change during the day Wednesday. Use small slope tests and shallow hand pits to investigate the storm snow and how it bonds to the MLK crust. If you encounter surprising results or find more snow than expected, step back and reevaluate your terrain choices. Avalanche danger should peak during periods of heavy snowfall and blowing snow.

Weather forecasts indicate that this storm should pack quite the punch Tuesday night through Wednesday with significant snow accumulation and windy conditions. Some uncertainty exists around exactly how much precipitation will fall in the West North zone. However, we expect more than an inch of water before Wednesday evening, which should be plenty to create new storm slabs.  When in doubt, it can be prudent to seek out lower angle slopes.

Release of a soft cohesive layer (a slab) of new snow that breaks within the storm snow or on the old snow surface. Storm-slab problems typically last between a few hours and few days. Storm-slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.

You can reduce your risk from Storm Slabs by waiting a day or two after a storm before venturing into steep terrain. Storm slabs are most dangerous on slopes with terrain traps, such as timber, gullies, over cliffs, or terrain features that make it difficult for a rider to escape off the side.

Storm slabs usually stabilize within a few days, and release at or below the trigger point. They exist throughout the terrain, and can be avoided by waiting for the storm snow to stabilize.