31 Dec 2020

December 31, 2020


      Sunrise was at 08:11 Hrs Wednesday. -4 with a 20-30 KPH ESE wind. -2 in the valley.

      Snowing 2 cm per hour for a while Wednesday morning in the valley.

      Blackcomb was delivering the goods.

      Nice skiing in 7Th Heaven.

     A break in the storm around 14:00 Hrs.

     Wednesday Dec 30, 2020. 14:00 Hrs. -4 with a 20-40 KPH East wind. 0 Deg C in the valley.

     Goes image from Wednesday afternoon.

      Snowing hard after the break went through.

      Tropical moisture heading our way, Friday into Saturday.

Weather Observations for December 31, 2020 taken at 06:00 Hours.

2240 meters      -6, Winds were 10-15 KPH SE--Horstman Hut
2180 meters      -6, Winds were     0-5 KPH SSW--Whistler Peak
1860 meters      -4, Winds were     0-5 KPH SE --Rendezvous 
1835 meters      -4, Winds were   5-10 KPH S--Round House
1650 meters      -3, 9 cm in 12 Hrs, 18 cm in 24 Hrs, Base 172 cm --Pig Alley
1560 meters      -3, 8 cm in 12 Hrs, 17 cm in 24 Hrs, Base 114 cm--Catskinner
  660 meters      -2, Valley Temp, Max temp Yesterday was +0.2 18.6 mm of precip yesterday.

     As of 07:00 Hrs this am we have broken cloud and unlimited visibility.


Unsettled early this am with a ridge building in a Northerly flow aloft. Should see the sun later this morning, clouds move in this afternoon before the next wet, warm, windy front arrives Friday morning. For today we can expect the FL to rise to around 1400 m. The strong front tomorrow will be drawing moisture from the Pineapple States so the FL might exceed 1800 meters, hoping that it stays a bit lower. Some models are suggesting 1500 meters, time will tell. Friday's storm will be in a South Westerly flow aloft with winds 80-100 KPH and possibly stronger at 2240 meters. Light to heavy precip is expected Friday through Saturday. The brunt of the moisture will likely fall Saturday night. The FL is forecasted to drop back down to surface by Sunday. Drying trend on Sunday with a chance of some sunny breaks, but short lived as another strong front arrives for Monday into Tuesday. Guesstimates: 8-12 cm by Friday am, 30-40 cm above 1600 meters by Saturday am, 40-60 cm above 1600 meters by Sunday am, 5-10 cm by Monday am. 


      GOES IR image this am.

       Building weak ridge for today with unsettled weather. Overcast by later this afternoon.

      Strong front for Friday with wet, warm, windy weather. Warm at 1500 meters.

      Stronger frontal band for Saturday, hoping for slightly cooler temps.


     An avalanche has killed a ski tourer from Belgium in Switzerland. Article below.        Net Pic

      Avalanche control on Blackcomb produced Sz 1-3 Xe, Xy, Xt, Xl, Sc. Sz 3 in Lakeside

      Limited control work on Whistler,  Sz 1-1.5 Xe, Xl, Sc. Did not get into the alpine.

From the Sea to Sky Advisory:

Avalanche Summary

There were numerous explosives triggered storm slab avalanches reported on Wednesday, mostly size 1, with one size 2 and one size 3.

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. 

There were several other human triggered wind slab avalanches up to size 2 reported on Monday as well.

Snowpack Summary

There has been between 40-70 cm of recent snow in the region with strong southwest winds. The fresh snow has likely been redistributed by the wind, forming storm slabs in lee terrain features.

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. 


     16 cm at 675 meters yesterday am in Alpine Meadows.

      Busy morning in the town centre.

      It's looking alot like winter!!!

      Cornices are getting bigger.
      Max gust yesterday at 2240 meters was 103 KPH at 12:30 Hrs.

        There was a lot of snow in the valley by the end of the day.

                        Time to be considering-Tree Well & Snow Immersion Suffocation (SIS)

                 Very deep low heading our way, a bit of a weather bomb!! Explosive Cyclogenesis

      Bit of a break tomorrow than we get hit hard!!! Pressure as low as 920 MB.


Mount Chief Pascal Trees: Dec 29, 2020

Cayoosh-Laziest Boy Ridge Top: Dec 29, 2020

Sentinel Ridge: Dec 30, 2020

Chief Pascal: Dec 30, 2020

Steep Creek: Dec 30, 2020

Hanging Lake Area: Dec 30, 2020

Small Slide: Dec 30, 2020


I got hit by an avalanche: Norway

Powder Picker Dec 30, 2020: David Jones


 Belgian ski tourer dies in an avalanche in Lower Valais: Switzerland

Weak snowpack layers taking lives: Powder Canada

Explosive charges protect backcountry Skiers: Scientific American

Avalanche danger runs highest in years as state records one of its busiest months: Colorado 

Avalanches triggered by humans 'almost certain' for North Shore Mountains: NSSR 

Avalanche threat rises on Vancouver Island: Courtenay

Several avalanches involving persons-No Injuries: Austria

Why Arva?

Arva is a family owned company that has the 3rd largest sales of transceivers in the world. They were around in the 80’s when there was just one other company providing transceivers to skiers.

Arva are continually improving and making new standards for the industry.

Probes and shovels are made with aircraft aluminium , an Arva probe is 13mm thick, most companies are 12 mm and weigh the same. Only 1 other company has UIAGM approval for guides shovels and probes. That other company has 70 m search radius on transceivers, same as Arva Neo Pro but $100 plus more expensive. Arva airbags have two separate bags, the canister is with much higher pressure than others for quicker deployment. Arva do not have a fan or any electronics to set off the airbag, but neither do Barryvox, Ortovox or BCA. 

Arva likes to support initiatives like Wayne's blog that help to educate local skiers and portions from all sales go to help keep the blog going.

This weeks Special Fund raiser for the Wayneflanavalancheblog is an Arva Reactor 24 airbag with canister, Neo Pro transceiver, Raid 240 probe and Axe shovel. Starting bid is $1200 plus tax.
Arva believes that you need 4 things to travel safely in the backcountry on skis:

1) Proper training with a guide, AST Level 1, etc, etc

2) Great gear, Avalanche Airbag with a probe and shovel, transceiver with fresh batteries that you are familiar with and have practiced search and rescue with.

3) Local knowledge of the area you are going to, this can be from Avalanche Canada, Wayne Flann Avalanche blog, etc

4) Make sure the other 3 are reliable!

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