12 Apr 2021

April 12, 2021

      YESTERDAY:

      Crisp blue bird Sunday, 08:00 Hrs. -5 at 660 m. -8 at 1650 m.

     10:00 Hrs. +1 Deg C at 660 m. -5 at 1650 m.

      Some cloud development in the late am.

      12:00 Hrs. +6 Deg C at 660 m. -1 at 1650 m.

     14:00 Hrs. Broken Cloud. +8 Deg C at 660 m. 0 Deg C at 1650 m.

     18:00 Hrs. + 7 at 660 m. -1 at 1650 m.


      Just before sunset Sunday evening.



Weather Observations for April 12, 2021 taken at 06:00 Hours.

2180 meters      -8, Winds were 10-15 KPH NNE--Whistler Peak 
1835 meters      -7, Winds were   5-10 KPH NNE--Round House
1650 meters      -8,  0 cm in 12 Hrs, 0 cm in 24 Hrs, Base 283 cm --Pig Alley
  660 meters      -5, Valley Temp, Max temp Yesterday was +9.0, 0.0 mm of precip yesterday.


      As of 06:25 Hrs, sunrise-we have clear skies and unlimited visibility.


 FORECAST:

Upper level ridging will continue to bring sunny weather to the area in a Northerly flow aloft. The FL today could go as high as 1800 meters, dropping back down to around 800 meters tonight. By Wednesday the FL could rise well above the local peaks. No real change expected until Sunday when the blocking pattern shifts, will likely see some cloudy skies by then. Possible precipitation by Monday, more on that later in the week. 


      GOES image from this am.


      High pressure the dominant force in the upcoming week. May see some cloud development.





      Northerly flow aloft.

.          Blocking pattern well established. Thermal trough with warm offshore flow.






      Low to the North, Low to the South.

Sunny skies over most of B.C.



      AVALANCHE ACTIVITY:

      Family involved in an avalanche in Norway. Mother barely escapes. Article below.            Net Pic


     Sz 3 Na likely from Saturday. ESE aspect. Between Angelo & Benvolio. MIN report below. Reid Pic


      Recent Sz 1 Na wind slabs in the Ashlu Area                                                             Greg Dixon Pic

      New wet loose on Armchair Glacier.


From Sea to Sky Avalanche Advisory:

Avalanche Summary

Saturday's MIN was active! Many users in the Sea to Sky and in adjacent regions encountered unstable snow conditions. Avalanche activity appears to have been limited to the depth of our latest storm snow, which was substantial in southern parts of the region. Wind loaded features were (unsurprisingly) especially reactive.

Looking forward, Monday's concerns should be limited to lingering wind slabs and predictable wet loose activity connected to daytime warming. Tuesday ushers in the start of a dramatic warming trend that will begin to expand the extent of wet loose concerns to higher elevation, more shaded aspects and may eventually test deeper snowpack layers.

Snowpack Summary

New surface melt-freeze crusts formed on solar aspects by the end of the day Saturday atop 10-30 cm of new snow, tapering with elevation and toward the north of the region, that accumulated through Friday night. Strong to extreme south and east winds have left behind varying levels of wind effect on many aspects in open terrain. Whistler Peak saw gusts of up to 140 km/h during the storm. 

Overall the new snow is likely to have now established a solid bond with the previous surfaces of crust, wind effect, and settled storm snow, however isolated slabs in steep, wind loaded features may remain reactive to human triggering. 

Solar warming will break down surface crusts and encourage wet loose releases -both natural and human triggered- each day on solar aspects and increasingly toward shaded alpine terrain as freezing levels march upward over the coming days.

Cornices are large and looming along ridgelines and formed fragile new growth during Friday's storm. Their release is unpredictable, requiring a large berth if you're travelling above or below them. Forecast rising freezing levels will increase the chances of cornice releases.



      INFORMATION & OBSERVATIONS:

     Some cloud development before noon on Sunday.


      Getting some exercise in a closed area!!

      Nice snow on the Ashlu Glacier. Will not last much longer with rising FL's.   Greg Dixon Pic


      Cornice debris from March still visible in Blackcomb Bowl.


      Mount Currie backside later in the afternoon.


FROM SEA TO SKY MIN REPORTS:

Chief Pascall Wind Slabs: April 11, 2021

Serratus Sunday: April 11, 2021

Journeyman: April 11, 2021

Deep Spearhead: April 11, 2021



VIDEOS:

Old footage, but a very large avalanche: Austria

Wet snow avalanche involvement: Norway


ARTICLES:

Father and two children were involved in an avalanche, Mother barely escaped: Norway

Solar Warming: Avalanche Canada

Loose Wet Avalanches: CAIC

ENSO Update-April 8, 2021: NOAA

No comments:

Post a comment