YESTERDAY:
Sunrise Sunday was at 08:11 Hrs. -6 with a 10-15 KPH SE wind. 0 in the valley.2240 meters -6, Winds were 10-20 KPH NNE--Horstman Hut
1860 meters -5, Winds were 0-5 KPH NNE --Rendezvous
1560 meters -5, 5 cm in 12 Hrs, 11 cm in 24 Hrs, Base 100 cm--Catskinner
FORECAST:
Some lingering cloud this am will dissipate as a ridge of high pressure builds into the area in a North Westerly flow aloft. The FL will rise and hover in the 900 meter range. Unsettled Tuesday am with mostly cloudy skies as the next front moves onshore. Should see light precip by late Tuesday afternoon continuing into Wednesday as another fontal band arrives. Unsettled Thursday with some periods of light snow. A potent front arrives for Friday and Saturday. Guesstimates: 0 cm by Tuesday am, 14-18 cm by Wednesday am, 2-6 cm by Thursday am.
AVALANCHE ACTIVITY:
An avalanche near Berthoud Pass, CO has killed a ski tourer. Article below. CAIC PicFrom Sea to Sky Advisory:
Avalanche Summary
Storm slabs and cornices were reported to be touchy during the storm on Saturday, skier end explosive control work producing storm slab avalanches size 1-2.
Last week, numerous wind slab avalanches were reported, triggered naturally and by riders at treeline and alpine elevations. Check out these MINs for a few examples: here, here and here.
A few large avalanches were observed last week, running on buried weak layers (described in snowpack summary). Most occurred on north to east aspects in the alpine. A size 2.5 reported Thursday from a coastal glaciated area west of the Squamish river was on a southeast aspect, 100 m wide with crown depth 40-80 cm deep.
Snowpack Summary
15-30 cm of recent snow has been redistributed by strong south to east winds, depositing deep pockets of storm slab into lee terrain features.
Two potential concerning weak layers may be present in the snowpack:
- The shallower layer, around 60 to 100 cm deep, includes feathery surface hoar crystals. This layer may be found in sheltered terrain features at treeline and lower alpine elevations but has been reported as spotty across the region.
- The more widespread weak layer includes sugary faceted grains that overlies a hard melt-freeze crust. This layer ranges in depth from 10 cm to 120 cm due to the wind scouring and loading the snow in different terrain features over the past two weeks. The layer has been reported as being widespread up to around 2000 to 2200 m.
To date we have mostly seen sporadic avalanche activity on these layers, but they remain possible to trigger where they exist in the mountains.
The remainder of the snowpack is well-settled.
LOCAL AVALANCHE CANADA MIN REPORTS:
Round Mountain: Dec 26, 2020
Hanging Lake: Dec 27, 2020
Oboe: Dec 27, 2020
Paul Ridge Observations: Dec 27, 2020
Cayoosh Armchair Glacier: Dec 27, 2020
VIDEOS:
Powder Picker Dec 27, 2020: David Jones
Sketchy Snowpack: Colorado
ARTICLES:
Berthoud Pass Backcountry skier becomes fourth avalanche fatality this season: Colorado
One soldier dead, one missing after avalanche in Turkey: Hakkari
12 mountaineers have been killed in Tehran avalanches: Iran
Skier survives an avalanche in the Pyrenees, video in article: Astun Station
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