Avalanche Forecast
Issued: Feb 19th, 2013 8:42AM
The alpine rating is Wind Slabs, Persistent Slabs and Cornices.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Poor - Timing, track, or intensity of incoming weather is uncertain on Friday
Weather Forecast
Wednesday: Freezing Level: 500m Wind: SW, initially moderate increasing to strong by sundown. 5 â 10 expected during the day. Thursday: Freezing Level: 500m Wind: Strong SW backing off of to moderate SW in the evening. 5 - 15 cm expected during the day. Friday: Freezing Level: 500m Wind: Strong S decreasing to light W after dark. 10 -25 cm expected during the day.
Avalanche Summary
Soft slabs up to 25 cm in depth on N aspects around 1400m were reported Monday. Yet another size 3 avalanche that went to ground was reported Monday on a rocky convexity with a shallow snowpack. This was in the same area where a wind loaded NE facing slope around 1400m released naturally to ground resulting in a size 3 avalanche on Sunday.
Snowpack Summary
The storm on Friday the 19th left between 20 - 60 cm in it's wake with the Northern portion of the region receiving the most snow along with a significant amount of wind that created large deep hard slabs. Most of the precip from the last storm fell as rain below 1200m or so which resulted in a crust below treeline. The region received another 20 cm or so Monday along with some moderate winds from both the west and possibly even east which created soft slabs that were sensitive to skier triggering on Monday.There are a variety of old interfaces now down 40 - 100cm which include facets, crusts and isolated pockets of surface hoar. There is very limited information about the nature of this interface. I would stress the importance of digging down to find and test weak layers.A strong mid-pack currently overlies a weak base layer of facets/depth hoar. It is worth noting that the snowpack in general is quite shallow compared to averages; triggering the basal weakness may still be possible from thin spots, rocky outcrops or under the weight of larger triggers such as cornice fall.
Problems
Wind Slabs
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Cornices
Aspects: North, North East, East.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Feb 20th, 2013 2:00PM