1 Jan 2021

January 1, 2021

     YESTERDAY:                     Happy New Year

     Early Thursday am.

     Blackcomb did a great job of getting the alpine open early.

     Cool light in the am.

      Clouds began to move in by mid morning.

     Moist marine layer pushed in by noon.

     There were some good turns to be had.


     Thursday Dec 31, 2020. 14:00 Hrs. -3 with a 10-25 KPH WNW wind. +1 in the valley.


      Over cast in the late afternoon.


Weather Observations for January 1, 2021 taken at 06:00 Hours.

2240 meters      -5, Winds were 75-105 KPH ESE--Horstman Hut
2180 meters      -5, Winds were   65-85 KPH SE--Whistler Peak
1860 meters      -3, Winds were   25-40 KPH SE --Rendezvous 
1835 meters      -3, Winds were   20-40 KPH ESE--Round House
1650 meters      -1, 12 cm in 12 Hrs, 12 cm in 24 Hrs, Base 178 cm --Pig Alley
1560 meters      -2,   6 cm in 12 Hrs,   6 cm in 24 Hrs, Base 114 cm--Catskinner
  660 meters       0, Valley Temp, Max temp Yesterday was +3.5, 5.9 mm of precip yesterday.


     As of 07:00 Hrs we have overcast skies, limited visibility, and snowing 2-3 cm per hr.


FORECAST: 

A warm front will push through this am with steady light to moderate precip in a South Westerly flow aloft. A trailing cold front will push through by this afternoon. Wet, warm, and windy weather for today with the FL possibly spiking to 2000 meters. Wishing it to rise to around 1600 meters and hover in the 1400 m range. Time will tell.  Should see the winds increase just before the arrival of the cold front this afternoon. A more vigorous front for Saturday with slightly cooler temps , moderate to heavy precip and high winds. The FL will hopefully drop to around 1300 meters. By Sunday morning it dries out with unsettled weather, even a chance of some sunny breaks in the afternoon. Another frontal band arrives on Monday. Guesstimates: 30-40 cm above 1800 meters by Saturday am, 40-50 cm above 1500 meters by Sunday am, 2-6 cm by Monday am, 18-22 cm by Tuesday am. 


      GOES IR image from this am.


       Wet, warm, windy weather for today with a rising FL.





       Vigorous frontal band for Saturday with slightly cooler temps.





      Unsettled Sunday, mostly cloudy with some periods of light precip. Fl will drop to surface.


     AVALANCHE ACTIVITY:

     Avalanche control produced numerous Sz 1-1.5 Xh, Xe, Sc on Whistler. Some Sz 2-2.5 on PWL.

      Heli Bombing in Flute Area.


     Sz 2 Xh on 201209 MFcr/FCxr Lakeside Traverse

      Sz 1.5 Xh on Ladies First.

      AC on Blackcomb produced Sz 1-2 Xh. Sz 1 Sa.

From Sea to Sky Advisory:

Avalanche Summary

Avalanches are expected to be widespread on Friday.

At the time of publishing, there were a few reports of explosives triggered avalanches up to size 2.5. At least one of these failed on the persistent weak layer mentioned in the snowpack summary.

There was a fatal avalanche in the South Coast Inland region (near the Sea to Sky boundary) north of Pemberton in the Railroad Pass area on Monday that resulted in two fatalities. It was reported to be a size 2 persistent slab avalanche on a west aspect, around 1650 m. The RCMP press release can be viewed here, and the Avalanche Canada report can be found here.  

A size 2.5 avalanche was triggered on Monday by a skier on Rainbow Mountain, which resulted in a full burial and, thankfully, a successful rescue. The avalanche failed on a 60 cm deep crust and facet layer on a northeast aspect around 1800 m. 

A natural size 3 persistent slab avalanche was reported on Mount MacBeth on Monday, check out this MIN report for details of this observation.

These avalanches highlight the ongoing potential to trigger persistent weak layers in the snowpack. 

Snowpack Summary

With 20 cm of new snow expected on Thursday night and another 30-40 cm in the forecast for Friday, storm slabs will be widespread.

This new snow will bring recent storm snow totals to over 100 cm.

The snowpack is currently complex, and two 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 sit on top of a hard melt-freeze crust. This layer ranges in depth from 20 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. 

There have been several recent human triggered avalanches on these layers. 


      INFORMATION & OBSERVATIONS:

      Stratus layer in the valleys to the North.

     Pyroclastic and Cayley.

.
      Nice snow in 7Th Heaven 

     There were some nice sunny breaks in the am.

      Awesome light in the afternoon.

      Natural Slab observed in the Whistler Backcountry.

      Let's hope the FL co-operates. 


LOCAL AVALANCHE CANADA MIN REPORTS:

Natural avalanche & whomping on Paul Ridge: Dec 30, 2020

Sky Pilot Trees: Dec 31, 2020

Decker: Dec 31, 2020

Cayoosh: Dec 31, 2020


VIDEOS:

Powder Picker Dec 31, 2020: David Jones

Tree Well Rescue: South Chilcotins


ARTICLES:

A ski tourer has died after falling into a tree well in the Brandywine area: Sea to Sky Backcountry

Snowboarder rescued after avalanche on Mount Washington: Vancouver Island

Snowboarder falls into a sinkhole in Sea to Sky Backcountry: Winter Adventure Warning

Large Remote Triggered Persistent Slab: CBAC

The bittersweet rise of the backcountry: Colorado

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