4 Apr 2021

April 4, 2021

      YESTERDAY:

      Fresh snow in the valley Saturday am. 0 Deg C at 660 meters.

      Continued snowing in the valley until just before noon.

      Freezing level started climbing around noon. +2 in the valley.


      At 13:30 hrs we had light rain in the valley. +3 Deg C in the valley. 0 Deg C at 1650 meters.

      At 14:30 Hrs it was raining in the valley. +5 Deg C. 0 Deg C at 1650 meters.


      19:00 Hrs. Still raining lightly. + 5 Deg C in the valley. -1 at 1650 meters.
 
      Satellite image from same timeframe as above




Weather Observations for April 4, 2021 taken at 06:00 Hours.

2180 meters    -10, Winds were 25-30 KPH N--Whistler Peak
1835 meters      -9, Winds were  20-30 KPH S--Round House
1650 meters      -8, 6 mm in 12 Hrs, 14 cm  in 24 Hrs, Base 293 cm --Pig Alley
  660 meters      -1, Valley Temp, Max temp Yesterday was +5.2, 5.4 mm of precip yesterday.


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


FORECAST:

Weak upper ridge of high pressure will bring a sunny day in a North Easterly flow aloft. The FL is hovering just below surface and will rise to around 1500 meters with daytime heating, dropping back down to surface tonight. A few scattered clouds in the mix this am but the ridge will strengthen by the afternoon. Flat ridge will continue to bring sunny conditions on Monday with some cloud development in the afternoon.  Unsettled for Tuesday with a mix of sun and cloud, increase in cloud cover later in the day as another cool upper trough arrives late Tuesday night into early Wednesday morning with periods of light precipitation.  Unsettled Thursday with a mix of sun, cloud, and flurries. Another front arrives for Friday. Guesstimates: 0 cm by Monday am, 0 cm by Tuesday am, 1-3 cm by Wednesday am, 12-18 cm by Thursday am, 1-3 cm by Friday am, 20-25 cm by Saturday am.


      GOES IR image from this am.


      Ridge building for today with mostly sunny skies. 850 MB image.





        North Easterly flow aloft this am. 500 MB image.


       Flat ridge will bring mostly sunny skies for Monday.


 



       Unsettled weather on Tuesday with an increase in cloud as the low pushes South.


      Mix of sun and cloud for Tuesday.


     AVALANCHE ACTIVITY:

      Example of a wet loose avalanche. Article below about them.                       Karl Birkeland Photo

      MIN reports below, some Sz 1 activity on the Duffey reported yesterday.


From Sea to Sky Avalanche Advisory:

Avalanche Summary

Storm and wind slab avalanches were likely triggerable on Saturday and into the night at high elevations. The snow could still be triggered on Sunday for areas that received sufficient snowfall.

Snowpack Summary

You may find around 10 to 20 cm of snow from Saturday's storm above 1600 m. The snow fell with strong southeast wind, so wind slabs may be found at high elevations on lee terrain features. The snow overlies a hard melt-freeze crust everywhere except for wind-affected snow on north aspects above 1600 m, so it could take a few days to bond to underlying surfaces. If sunny skies prevail on Sunday, the snow may moisten on sun-exposed slopes. Below around 1600 m, the snow is likely wet or has frozen into a hard melt-freeze crust.

Cornices are large and looming along ridgelines. Their release is unpredictable, requiring a large berth if you're travelling above or below them.


      INFORMATION & OBSERVATIONS:

      Snowing 2 cm per hour Saturday am in the valley.

      South end of Green Lake is presently ice free.

      Swimming around in a slurry.




FROM SEA TO SKY MIN REPORTS:

Steep Creek: April 3, 2021

Vantage Ridge, South Side: April 3, 2021


VIDEOS:

Wet Snow Hazards in the Bridgers: Montana


ARTICLES:

Spring is coming: Avalanche Canada

Fernie's avalanche rescue dogs: Meet the Team

Example of a wet loose snow avalanche: Colorado

Hot weather further destabilizing the snow: Missoula Avalanche

Must Read "Avalanche Craft" by Bruce Jamieson: Powder Cloud

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