The weather DJ seems to have left the buliding and the weather pattern continues to be stuck on repeat. Sunshine, sunshine, sunshine… Yesterday cloudy skies in the middle of the day were almost a tease. Today there will be an uptick in afternoon NW winds to add a little spice but really the story remains the same. We have seen 20 days without any precipitation and nine days since a wind event impacted our region. Despite the weather and snowpack conditions being mostly stable and the weak layers dormant, a hard wind slab 12-18” deep was triggered by a snowmachiner three days ago on a SE aspect of Seattle Ridge. This is a good example of a wind loaded terrain feature still harboring unstable snow and a good reminder that LOW danger does not mean NO danger. Kicking off even a small wind slab or loose snow avalanche in steep terrain may have high consequences. Things to keep in mind if you are headed to the mountains today:
Wind Slabs: Old and hard winds slabs are easy to find but for the most part they are locked into place. Smooth pillowed snow on steep unsupported features or in rocky areas will be the most suspect zones for someone to initiate an old wind slab. Pay attention to blowing snow today if the NW winds start to pick up any soft snow. There is not much left to transport. Watch for shooting cracks if slopes are actively being loaded.
Loose Snow Avalanches (Sluffs): Dry sluffs on steep slopes are probable and have been fast moving this week.
Glide Avalanches: Glide cracks continue to slowly open above popular terrain on Seattle Ridge and in other areas of the advisory area. These could release at any time, watch for these cracks and avoid being under them.
Cornices: Cornices should always be given a wide berth from above and limit exposure time traveling underneath.
Persistent Slabs and Deep Slabs: There are various weak layers in our thin snowpack. Buried surface hoar sits 1-3+’ below the surface and faceted snow sits in the mid and base of the pack. These weak layers with varying degrees of strength are in a dormant stage due to plenty of time to adjust with a lack of changing weather. Although its unlikely, an avalanche breaking deeper in the pack isn’t completely out of the question in Johnson Pass, Lynx Creek and in parts of Girdwood Valley (especially around Crow Pass).
This hard wind slab was initiated by a snowmachine just below the trees, lookers left side of photo, while exiting the slide path. This was on a SE aspect of Seattle Ridge at 2400′ in an area near ‘God’s Country’. Photo by Brian Bird.
High clouds over Seattle Ridge yesterday. Note the series of glide cracks along the ridge that continue to open.
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