Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches possible, human triggered probable.
Below Treeline
Natural avalanches unlikely, human triggered possible.
Alpine
Natural and human triggered avalanches likely.
Treeline
Natural avalanches possible, human triggered probable.
Below Treeline
Natural avalanches possible, human triggered probable.
Alpine
Natural and human triggered avalanches likely.
Treeline
Natural and human triggered avalanches likely.
Below Treeline
Natural and human triggered avalanches likely.
Regions
Glacier.
Deep reactive layers and another series of storms approaching deserve your attention. The snowpack this year is challenging, and has been surprising recreationalists and professionals alike. Be very cautious if you head into the backcountry.
Weather Forecast
A quick moving front will pass through the area today, bringing ~10cm with strong SW winds. A strong storm will arrive on Sat afternoon. Up to 20cm of snow is expected Sat, with moderate SW winds transporting snow and rapidly loading slopes. Another 16cm is expected Sunday. Freezing levels should stay below 1400m.
Snowpack Summary
Last weeks storm snow has settled over the March 2 crust down ~1m. Instabilities within the slab, and the crust, are becoming unreactive. The Feb 10 interface is down 1.5-2m and continues to react in snowpack tests. It has been most reactive recently on solar slopes, see below. Below this, the mid to lower snowpack is well settled.
Avalanche Summary
Yesterday, a group of ski tourers remotely triggered a size 2.5 avalanche from the thin rocky ridge at 2650. The avalanche failed over 30m away on a S aspect. It was ~1m deep, likely failing on the Feb 10 PWL, and ran over 400m. With the recent sunshine, numerous natural solar triggered avalanches to size 3 have been occurring daily.
Confidence
Timing, track, or intensity of incoming weather system is uncertain
Problems
Persistent Slabs
Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). 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.
