Avalog Join
Archived

Avalanche Forecast

Apr 11th, 2023–Apr 12th, 2023
Alpine
2: Moderate
The avalanche danger rating in the alpine will be moderate
Treeline
2: Moderate
The avalanche danger rating at treeline will be moderate
Below Treeline
2: Moderate
The avalanche danger rating below treeline will be moderate
Alpine
2: Moderate
The avalanche danger rating in the alpine will be moderate
Treeline
1: Low
The avalanche danger rating at treeline will be low
Below Treeline
1: Low
The avalanche danger rating below treeline will be low
Alpine
2: Moderate
The avalanche danger rating in the alpine will be moderate
Treeline
1: Low
The avalanche danger rating at treeline will be low
Below Treeline
1: Low
The avalanche danger rating below treeline will be low

As the freezing level falls overnight and then warms during the afternoon, you will find that conditions change rapidly through the day. Be cognizant that daytime warming can rapidly destabilize the upper snowpack.

Confidence

Moderate

Avalanche Summary

On Monday in neighboring Waterton National Park, numerous loose wet avalanches up to size 2.5 were reported on all aspects and elevations during the warm, wet storm.

If you have any observations from this region, let us know what you are seeing by submitting a report to the Mountain Information Network.

Snowpack Summary

In the alpine and around treeline, 5-10 cm of new snow covers rain soaked surfaces. Prior to the weekend storm, dry snow only remained on shaded (northerly) slopes.

The mid snowpack is generally settled and strong at treeline and above.

A melt-freeze crust that was buried in mid January can be found 60 to 100 cm below the snow surface.

A weak layer of large, sugary crystals persists at the base of the snowpack. This layer has not produced recent avalanche activity in this area, but professionals continue to monitor for signs of it becoming active.

Weather Summary

Overnight cooling followed by afternoon rising freezing levels and warming is likely to unconsolidated and rapidly settle the upper snowpack especially on south aspect terrain when the sun appears. Prepare to continually evaluate the conditions, and change plans as necessary.

Tuesday Night

Cloudy. Trace amounts of snow. Freezing level descending to 1000m, Alpine temperature low of -9°C. Moderate to strong southwest ridgetop wind.

Wednesday

Clearing with some cloud. Trace amounts of snow. Freezing level rising to 1700m, Alpine temperature low of 0°C. Light southwest ridgetop wind.

Thursday

Cloudy. 1 to 5cm of snow. Freezing level rising to 1700m, Alpine temperature low of 0°C. Light Northeast ridgetop wind.

Friday

Cloudy. 1 to 5cm of snow. Freezing level rising to 1700m, Alpine temperature low of 0°C. Light Northeast ridgetop wind.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Continue to make conservative terrain choices while the storm snow settles and stabilizes.
  • Be alert to conditions that change with aspect and elevation.
  • Be alert to conditions that change throughout the day.
  • Watch for unstable snow on specific terrain features, especially when the snow is moist or wet.
  • The more the snow feels like a slurpy, the more likely loose wet avalanches will become.

Avalanche Problems

Storm Slabs

Tuesday snowfall overlies a warm and moist surface and is likely to be bonding well. Expect during periods of daytime warming potential for increased sensitivity to triggering will exist as the storm slab settles rapidly.

Past strong southwest alpine wind could be stripping ridges down to rock, or rapidly loading leeward terrain.

Use extra caution around ridgecrests, rolls, and on convex slopes. Retreat to mellower terrain if you find signs of instability like shooting cracks, whumpfs, or recent avalanches.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Likely

Expected Size: 1 - 2

Loose Wet

Past moderate rainfall up to 2500 m, has unconsolidated the upper snowpack. Expect a good recovery and refreeze overnight Tuesday, however the expected daytime warming will continue to support loose wet avalanches as a problem at lower elevations and especially on south aspect terrain when the sun makes an appearance.

Watch for signs of a loose, wet snowpack, like snow pinwheeling or snowballing down the slope, or surface snow that looks and feels like a slurpy.

Aspects: All aspects.

Elevations: Treeline, Below Treeline.

Likelihood: Likely

Expected Size: 1 - 2