We are coming out a large avalanche cycle, as cold weather has curbed the amount natural activity. Human triggering is still likely.
80 cm of recent snow with strong gusts out of the north/east continue to build slabs in uncommon areas. Use caution in all lee areas with wind effect and watch for wind loading occurring above you. These avalanches may start small, but have the potential to step down to the deeper weak layers and create large avalanches.
Slabs 80-120 cm deep overlie three persistent weak layers formed in January which are a mix of crusts on solar aspect, facets on northerly aspects and isolated surface hoar. These avalanches could also step down to the Nov facets and become even larger.
Facets and depth hoar at the bottom of the snowpack provide weak support for the entire snowpack. Incremental snowfall since the start of February has brought the overlying slab to the tipping point and we have started to see large, destructive avalanches failing on the November facets and running a long distance.
Today we saw continued evidence of the natural cycle in the last 24/48h, with multiple naturals up to size 3 out of all aspects in the alpine.
Bombing today in the 93S area today produced results up to size 2.5, with the failure plane being the recent storm interface.
Up to 80 cm's of storm snow over the several days has begun to settle into windslabs in the alpine, treeline and into the below treeline region. These slabs have been formed primarily by north and east winds. Expect them in places you may not normally see them. While becoming less reactive to human triggering, they can still be sensitive. There are crusts in the middle of the snow pack and the base of the snowpack is still weak with basal facets. Test profiles done today are still producing sudden results in the basal facets.
We're in the middle of the cold snap. Alpine temperatures will remain in the -25 to -30 range, with wind chill to -40 in exposed areas! Cloudy skies with some flurries expected in the morning, giving way to clearer skies in the pm. Thursday evening into Friday morning will be the coldest time of this cold snap. Not a good night to be caught out!
More details can be found in the Mountain Weather Forecast.
