15 Feb 2021

February 15, 2021

     YESTERDAY:

      Sunrise Sunday was at 07:24 Hrs. -12 with a 20-25 KPH ESE wind at 2240 meters.

     Snowing lightly in the am.

      805 cm of snow so far this season recorded at 1650 meters.

     Clouds got thinner mid morning.


     A few breaks in the am.

     There was some great light in the am.

     There were some great cold snow conditions.

      Sunday February 14, 2021. 14:00 Hrs. -7 with a 10-20 KPH ENE wind. -5 in the valley.

      GOES image from later on Sunday afternoon.


      Flurries for most of the day. Faceted snow, skiing very well.


Weather Observations for February 15, 2021 taken at 06:00 Hours.


2240 meters      -8, Winds were   5-10 KPH ESE--Horstman Hut
2180 meters      -8, Winds were 30-40 KPH ESE--Whistler Peak
1860 meters      -6, Winds were     0-5 KPH ESE --Rendezvous 
1835 meters      -6, Winds were     0-5 KPH E--Round House
1650 meters      -6,  4 cm in 12 Hrs, 6 cm in 24 Hrs, Base 244 cm --Pig Alley
1570 meters      -5,  4 cm in 12 Hrs, 5 cm in 24 Hrs, Base 177 cm--Catskinner
  660 meters      -6, Valley Temp, Max temp Yesterday was -4, 0.7 mm of precip yesterday.



      As of 07:00 Hrs this am we have overcast skies, limited visibility and its snowing lightly.


FORECAST:

An upper trough will bring periods of light snow this am in a Westerly flow aloft. Unsettled weather this afternoon with a mix of sun and cloud , seasonable temps. The FL may go up to 1000 m but should hover between surface and 800 meters. Ridge moves in on Tuesday with a chance of some flurries in the am with a mix of sun and cloud for most of the day. Ridge strengthens Wednesday with sunny skies. Thursday a front pushes through with a much needed reset. A series of frontal bands will keep the weather active into next week. Guesstimates: 2-5 cm by Tuesday am, trace-1 cm by Wednesday am, 0 cm by Thursday am, 10-15 cm by Friday am. A decent dump looks to arrive on Sunday.


      GOES IR image from this am.

      Upper trough for today will leave the area by this afternoon with unsettled weather in its wake.





     Westerly flow aloft today, will switch to Northwesterly by Tuesday.


         Ridge begins to build on Tuesday with unsettled weather.





      Ridge strengthens for Wednesday with sunny skies.

R
     Ridge builds for Wednesday.

      Low pushes in on Thursday with some pow.

      AVALANCHE ACTIVITY:

      An avalanche has killed a snowboarder on Mt Trelease, CO. Article below.                     CAIC PIC

      An avalanche has killed a snowmobiler near Rollins Pass, CO. Article below.                    Net Pic

     1 Dead, 1 injured in an avalanche on BeeHive Basin near Big Sky. Article below. Facebook Pic

      An avalanche has killed a mountaineer on Prenj Mountain, Bosnia. Article below.    Net Pic

     On Whistler a few Sz 1 Na on steep North aspects.

     Heli bombing on Blackcomb yesterday PM, Sz 2 Xh on Way Poopy, Sz 1.5 Xh on Halifax


AVALANCHE SUMMARY FOR SEA TO SKY AREA: 

Avalanche Summary

Another fatal avalanche involvement occurred in the region on Saturday in the Brandywine valley. The person caught was carried several hundred metres over steep, rugged terrain and through treed slopes below. The avalanche is described as a size 1 (small) wind slab on a southwest aspect at 1700 metres. The incident report can be seen here.

On Friday, a large (size 2.5), fatal avalanche was triggered by skiers at 2200 metres on a west-facing slope on Phalanx Mountain. The avalanche is described as a wind slab that formed to the lee of recent strong east winds. Two people out of a group of three were involved in the avalanche and one person was killed. The incident report can be seen here. A second, smaller (size 1.5) wind slab was triggered by skiers on a nearby slope, again causing injury to the person involved.

A bout of strong northerly winds on Thursday caused conditions in the region to change rapidly, with new and touchy wind slabs forming in unusual places. Numerous natural releases from size 1 to size 2 were observed in the Whistler area above about 1900 metres on and since Thursday. 

It is important to note wind has not affected elevation bands uniformly across the region, with heavy wind effect and slab formation noted even below treeline in some areas. This is a critical piece of information as new snow obscures existing wind slab formations.

Two more skiers were involved in an avalanche in the Supercouloir feature of Mamquam Mountain on Thursday. This avalanche was a natural wind slab release ands again resulted in serious injuries and an urgent evacuation by helicopter.

Snowpack Summary

About 15 cm of new snow (over a two day period) is expected to accumulate in the region by the end of the day on Monday. This will feed into existing wind slab problems brought on by powerful east and northeast winds that have been redistributing loose snow into reactive wind slabs. Winds have been circling the compass as we wait for a forecast shift to the southwest, expanding problems to all aspects.

Forecast snow will otherwise add to around 15 cm of older low density snow in shaded, sheltered areas and to more widespread wind-affected snow. This previous surface snow has been transforming into weak, faceted grains under recent cold temperatures. On solar aspects, a thin recent sun crust may be found near the new snow interface or beneath recently wind transported snow. Both of these interface types are contributing to the reactivity of new wind slabs.

Below the evolving surface, 50-100 cm of settled storm snow sits on a persistent weak layer from late January that consists of facets at upper elevations, surface hoar in sheltered areas, a melt-freeze crust below 1900 m, and a sun crust on south-facing slopes. There could be more than 100 cm on this layer in wind loaded areas. Although this structure is suspect, we have no recent reports of avalanches failing at this interface within the region.

A crust from early December, currently considered dormant, may be found around 200+ cm deep in the snowpack.


      INFORMATION & OBSERVATIONS:

      The Arctic outbreak has made for some interesting roof lines.

      Black Tusk an old Stratovolcano.

      Sliding down Exhilaration would be exhilarating. He was OK. Not sure about the underwear!!

      Lots of AST courses.

      Many folks going into the backcountry.

      Extreme Terrain.

     Awesome day for a tour.

     Yes it was that easy to find some good turns.

     Yesterday we received 0.7 mm of precipitation at 660 m. 

      Seventh Heaven Lift. From 4 Km away.




RECENT MIN REPORTS FROM SEA TO SKY:

Avalanche fatality on Phalanx: Feb 12, 2021

Avalanche fatality in Brandywine Bowl: Feb 13, 2021

Backside of Disease: Feb 13, 2021

Rainbow West: Feb 13, 2021

Steep Creek Steep Slough: Feb 13, 2021

56: Feb 13, 2021

Oboe: Feb 14, 2021

Mount Chief Pascal: Feb 14, 2021



VIDEOS:

Natural Avalanche on Gothic Peak: Colorado

Powder Picker February 15, 2021: David Jones


ARTICLES:

Snowboarder, snowmobiler killed in two separate avalanches on Sunday: Colorado

An avalanche has killed a mountain climber on Prenj Mountain: Bosnia

Two lives lost to Avalanches in Whistler: Vancouver Sun

Snowboarder has died, another injured in an avalanche on BeeHive Basin: Montana

He survived an avalanche by clinging onto a tree. Then he started digging for his girlfriend: Utah

A snowboarder rescued after being completely buried in an avalanche: East Vail Backcountry

In Italy since the beginning of the year an avalanche every 3 days: Italy News

SFU Grad develops classification system to keep backcountry recreationalists safe: B.C.

Thinking in Risk: Powder Cloud


          Submit your best avalanche photo for a pair of  Goggles Feb 1-28, 2021. Sea to Sky Area.

                                                    Thanks to Volkl Canada for sponsoring.

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