2 Dec 2021

December 2, 2021

     YESTERDAY: 

     07:45 Hrs. Wednesday. Natural avalanche cycle in Blackcomb Bowl. +2 Deg C with 25-50 S wind.

      08:00 Hrs. +3 Deg C with 25-65 S winds. Hard to see but looks like a Na wet loose cycle.

      Warm temperatures in the valley have melted the valley snow.

     Wind, Wednesday deposited needles and branches on the wet snow.


Weather Observations for December 2, 2021 taken at 06:00 Hours.

2240 meters      -6, Winds were 20-40 KPH S--Horstman Hut
2180 meters      -6, Winds were 25-35 KPH S--Whistler Peak
1860 meters      -4, Winds were   5-15 KPH SE--Rendezvous
1835 meters      -4, Winds were 15-30 KPH S--Round House
1650 meters      -2, 2 cm in 12 Hrs, 2 cm in 24 Hrs. Base 110 cm --Pig Alley
1570 meters.     -2, Trace cm in 12 Hrs, trace cm in 24 Hrs. Base 92 cm. Catskinner
  660 meters     +4, Valley Temp, Max temp Yesterday was +8.5, 45.6 mm of precip yesterday


It was -1 at Pig Alley by midnight. Precipitation stopped at around 20:00 Hrs yesterday.

                                   As of 07:30 Hrs we have broken clouds and unlimited visibility.



FORECAST:

A ridge of high pressure will bring a mix of sun and cloud today in a Westerly flow aloft. The freezing level is hovering around 1000 m and will drop to below surface by tonight. Lingering cloud this am with sunny breaks on the way. A weak front arrives Friday evening with mostly high clouds for most of the day, may see a sunny break in the am. Models diverge on this happening but going with light snowfall Friday night into Saturday am. Ridging in the afternoon will bring unsettled weather with a mix of sun and cloud. Sunday at this time looks to be mostly cloudy, will depend on how much the low interacts with the high. More on that in Tomorrows post. No pineapple or Mango expresses in the near future. Looks seasonable for the next week. Guesstimates: 0 cm by Friday am, 4-8 cm by Saturday am (06:00), 0-1 cm by Sunday am.



GOES IR image this am.


      GOES 17 ABI Image 2021/12/2. 13:00 Z

      Surface ridge with much cooler temperatures for today.







      Westerly flow aloft today.


        Unsettled Friday, likely see some high clouds most of the day.









      Front arriving Friday night into Saturday am. Seasonable temperatures.


      Snow on Saturday.


      AVALANCHE ACTIVITY:

      Blackcomb, Wet Slabs observed to Sz 2 Na. Wet loose to Sz 1.

      Whistler Wet Slabs observed to Sz 2 Na, wet loose Sz 1-1.5 Na. Poor visibility in the alpine.


FROM AVALANCHE CANADA:

Avalanche Summary

A natural storm slab avalanche cycle occurred over Tuesday night. Details are still limited but it's safe to assume numerous large or even very large avalanches occurred during this period.

Looking forward, alpine areas where dry snow accumulated during the storm will remain a real concern for Thursday. Cooling temperatures should aid in stabilizing the snowpack but the alpine may need more time to adjust to the significant load of new snow.

Snowpack Summary

The warm, wet storm from early in the week brought 50+mm of precipitation to the region. Above about 2100 metres, this fell as snow (up to 50 cm) under the influence of extreme southwest winds. At these upper alpine elevations, the new snow added to 20-50 cm of previous storm snow. A breakable crust (from Nov 27) exists about halfway through its depth. 

The new and older storm snow collectively overlies a mix of surface hoar, decomposing grains and faceted snow resting on a melt freeze crust from mid-November. Surprising large avalanches sliding on these weak layers were reported during the last storm. 

Below the storm's snow line, a rain-wetted 50 cm of older storm snow overlies the same crust. Areas where wet snow exists at or very near the surface will quickly stabilize as temperatures cool Wednesday night.

Average snow depths at treeline are now likely closer to 150-200 cm; 250+ cm in the alpine. Snowpack depths decrease dramatically below treeline and may still be below threshold for avalanches in some areas.



      INFORMATION & OBSERVATIONS:

      South branch of the Horstman Creek. That is a lot of water!!!

      Warm temperatures have created some rock slides.

      Conditions have changed again, be cautious!!


      Image from 17:30 Hrs Wednesday. The AR that does not want to stop!!! Mango Express

      Seems surreal how far the moisture plume was coming from. Philippines!!



LOCAL MIN REPORTS:

No new reports as of 07:00 Hrs.


VIDEOS:

Rain or This: CBAC

Snowflakes: Dr Ken Libbrecht


ARTICLES:

More climbers died in avalanches than skiers here, and danger is extreme today: Gripped

Rain and heat create high avalanche risk near Vancouver: Avoid all avalanche terrain

Avalanche control creating difficulties for those heading to Alberta: HWY 1

Sunshine Ski Resort closed due to avalanche risk: Alberta

How to buy boots: Powder Cloud

1 Dec 2021

December 1, 2021

    YESTERDAY:

      Snowing to 1600 meters most of the day. Went from -1 at 11:30 to +4 at 21:00 hrs at 1570 m.

     Very wet snow at 1570 m.

      Avalanche closure at the top of Jersey Cream Chair Tuesday. AC had avalanche danger as extreme.




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

2240 meters       0, Winds were 45-100 KPH SE--Horstman Hut
2180 meters       0, Winds were 85-125  KPH S--Whistler Peak
1860 meters     +2, Winds were 20-45 KPH S--Rendezvous
1835 meters     +3, Winds were 35-90 KPH SW--Round House
1650 meters     +4, 42.3 mm in 12 Hrs, 60.5 mm in 24 Hrs. Base 120 cm --Pig Alley
1570 meters.    +4, 32.6 mm in 12 Hrs, 39.0 mm in 24 Hrs. Base 76 cm. Catskinner
  660 meters     +8, Valley Temp, Max temp Yesterday was +6.5, 34.9 mm of precip yesterday
 Strong winds affecting lifts this am. Should abate later this am.


      As of 07:00 Hrs this am we have overcast skies, variable visibility and raining lightly.




FORECAST:

Seems to be a lull in the precipitation this am, still more rain forecasted in a Westerly flow aloft. The AR event is forecasted to dip South again giving us periods of light/moderate precipitation into Thursday am. A cold front will pass tonight bringing snow to the upper elevations. The freezing level is hovering in the 2300 m range and should slowly drop to 1400 m by tonight. Precipitation should ease early Thursday am with weak ridging by the afternoon, should see a mix of sun and cloud with cooler temperatures. Friday is looking like a dry cloudy day with the freezing level below surface. A weak front will arrive Friday night into Saturday am with periods of light snow. A stronger front arrives Sunday depending on which models you like to use. Guesstimates: 20-30 mm above 1500 m, with 5-10 cm at 1500 m by Thursday am, 0 cm by Friday am, 2-6 cm by Saturday am,  2-6 cm by Sunday am.


      GOES image this am.

      GOES 17 ABI 2021/12/01 13:30 Z


        Front will continue to bring precipitation, looks like  slightly cooler temps by noon.






      Westerly flow aloft. 


        Much cooler by Thursday, FL below surface.








        Likely see some cirrus cloud with the next weak front arriving Friday night. Cold!!



      Looking cloudy on Friday. Weak front likely arriving early Saturday am.


      AVALANCHE ACTIVITY:

     Some control work on Blackcomb yesterday, Sz 1 ssl Xe Sc. 


      Minimal control work on Whistler yesterday. Some Sz 1-2 Xl Xe storm slabs. 


From Avalanche Canada: 

Avalanche Summary

Numerous natural and triggered avalanches, including large storm slabs avalanches (size 3 and 4) sliding on buried surface hoar and deeper buried crusts were reported during the last storm. We expect to see another widespread avalanche cycle during the current atmospheric river, with large, full-path avalanches.

Snowpack Summary

At elevations up to around 2500 m, significant amounts of rain is falling on new snow from earlier in the storm. Until temperatures cool, this will result in a wet, heavy, unstable upper snowpack.

A layer of surface hoar has previously been reported that is buried between 60-100 cm deep. Slightly below this layer is a crust with facets. Surprising large avalanches sliding on these weak layers were reported during the last storm.

Average snow depths at treeline are now likely closer to 150-200 cm; 250+ cm in the alpine. Snowpack depths decrease dramatically below treeline and may still be below threshold for avalanches in some areas. Early season hazards such as rocks, stumps, and creeks are still a concern at these lower elevations.



      INFORMATION & OBSERVATIONS:

      Catskinner weather plot from 06:30-14:30 received 4 cm of new snow (6.4 mm). Base 91 cm.

      Snowing at 1860 m around noon. 0 Deg C. By 22:00 Hrs it was + 3. 

     Ziggy is the latest avalanche dog in training.

      Warm temperatures have done a number on the valley snow. High Tuesday in the valley was + 6.5.


Here are the precipitation totals for November in the Sea to Sky Corridor. For some reason there is at least one day when no Data was recorded at each of these stations so totals are not 100 % accurate.
Squamish    580.6 mm
Whistler      387.0 mm
Pemberton   267.1 mm

From the WB Patrol:

Backcountry Access number has been repaired, old number 604-905-2334 now works.


LOCAL MIN REPORTS:

AST 2 at Blackcomb: Nov 28, 2021


VIDEOS:

Older footage, but some get lucky: Out running an avalanche


ARTICLES:

Update on the snowmobiler who died in an avalanche in Northern B.C.: Chetwynd

Forecasters warn against venturing into B.C.'s backcountry as avalanche danger rises: Avalanche Canada

Sign up for avalanche research on Avalanche Risk Management: SFU

Avoid all avalanche terrain--Rain & warmth create extreme risk near Vancouver: DailyHive

Whistler Snow Report and weather forecast guide: Rise&Alpine

30 Nov 2021

November 30, 2021

    YESTERDAY:

      Nice breaks Monday morning.

      Dust on crust.

      Across the valley.

      Variable conditions but nice snow on leeward slopes. Another crust under the fresh.


      Snowing at 1860 m Monday.

      Cloudier as the day progressed.



Weather Observations for November 30, 2021 taken at 06:00 Hours.

2240 meters      -4, Winds were 75-95 KPH SE--Horstman Hut
2180 meters      -3, Winds were 60-90 KPH S--Whistler Peak
1860 meters      -2, Winds were 15-30 KPH S--Rendezvous
1835 meters      -2, Winds were 25-70 KPH SE--Round House
1650 meters       0, 12 cm  in 12 Hrs, 13 cm in 24 Hrs. Base 128 cm --Pig Alley
1570 meters.      0,   7 cm in 12 Hrs ,   8 cm in 24 Hrs. Base 89 cm. Catskinner
  660 meters     +4, Valley Temp, Max temp Yesterday was +6.5, 4.1 mm of precip yesterday



      As of 07:00 Hrs this am we have overcast skies, limited visibility and it is snowing 2 cm per hr.


FORECAST:

Wet, warm, windy weather in a Westerly flow aloft for today. The freezing level is sitting at around 1600 m and is expected to rise to around 2400 m tonight. Expect periods of light to heavy precipitation into Wednesday with the FL slowly dropping on Wednesday from 2200 m to 1200 meters by Thursday am. Should see some snow at the weather plots as a cold front pushes through near the end of the AR event.  Weak ridging on Thursday will bring unsettled weather with a mix of sun and cloud with the FL dropping to surface by Thursday night. Friday is looking relatively dry with more seasonable fronts arriving on the weekend. Guesstimates: 45-55 mm at 1650 m by Wednesday am, 30-40 cm above 1800 m by Thursday am, 1-3 cm by Friday am. 


      GOES IR image from this am.

      GOES 17 ABI Image 2021/11/30. 13:00 Z


           Low sending a pineapple express our way today with rising temperatures.





     Westerly flow aloft.


      Cooler by Wednesday afternoon. Low sending moisture our way.






      Much cooler on Thursday with unsettled weather.


      Weak ridging for Thursday, likely will be mostly cloudy with some afternoon sunny breaks.


      AVALANCHE ACTIVITY:

      An avalanche has killed one snowmobiler in Northern B.C. Article below.                   AC Pic


      Recent avalanche activity on Whistler. Na, Xc, Xe, Xl produced Sz 2-2.5.

      Avalanche mitigation on Blackcomb produced several Sz 1-2 Xe.

      Wet debris in Blackcomb Bowl.

Avalanche Summary

Numerous natural and triggered avalanches, including large storm slabs avalanches (size 3 and 4) sliding on buried surface hoar and deeper buried crusts, have been reported Saturday during last storm. With another atmospheric river storm affecting the area Tuesday and Wednesday, expect to see a widespread avalanche cycle with the potential for large, full-path avalanches.

Snowpack Summary

Recent snowfalls and strong southerly winds are developing reactive storm slabs with thicker accumulations in leeward alpine and treeline features. This new snow continues to bury a surface hoar layer and a combo of thick crust / facets observed 50-100 cm down the surface in the alpine and at treeline. Surprising large avalanches sliding on these weak layers have been reported over the last few days. Heavy loading coming with this intense storm will likely produce more avalanche activity on these layers.

Average snow depths at treeline are now likely closer to 150-200 cm; 250+ cm in the alpine. Snowpack depths decrease dramatically below treeline and may still be below threshold for avalanches in some areas. Early season hazards such as rocks, stumps, and creeks are still a concern at these lower elevations.


      INFORMATION & OBSERVATIONS:

      To access information on the WB Backcountry Routes please read below notice.


From WB Patrol: Important notice

The Whistler Blackcomb Boundary Access Phone line @ 604.905.2324 has been experiencing technical difficulties. Until our telephone provider is able to resolve this issue please use this temporary number: 604.935.5824
Soon to go live this winter is an app on the WB website that will also have updates on the status of our boundaries



      Snow accumulating in the trees is always very welcome.

      Wind was transporting fresh snow above 2000 m Monday.

      You never know unless you actually get out in the elements.


LOCAL MIN REPORTS:

Disease Ridge: Nov 29, 2021


VIDEOS:

Weak Thin snowpack in: Montana


ARTICLES:

A snowmobiler has died in an avalanche in Northern B.C.: Avalanche Canada

Deadly avalanche in North: Pine Pass

A Ski patroller involved in an avalanche in the Aosta Valley: Italy

Extreme Avalanche Hazard in Sea to Sky Corridor: Avalanche Canada

How the increase in backcountry users is affecting avalanches: Higher Danger

Special weather advisory for: Whistler