Monday February 8, 2021

Wednesday February 10, 2021
Tuesday February 9, 2021
Monday February 8, 2021
Confidence: High -

Main Concerns

Persistent Slab, Wind Slab, Loose Dry - view Avalanche Problems for detailed information.

Travel & Terrain Advice

Be cautious when route-finding and avoid convex roll features.

Seek low angle terrain that is well supported.

Avoid travel on South aspect terrain during the period of warming and direct sun exposure.

Avalanche Summary

Confidence: High , Forecast team performed daily terrain travel and snowpack observation during the past forecast period. Numerous professional and public reports.

A well documented (view our Instagram page) natural avalanche was filmed on a North aspect , this wind slab was large size 2.

Wind slabs reported at tree line up to size 2 on steep southerly aspects directly below convex roll features, similar to feature described and filmed above.

During both Saturday and Sunday, many solar induced Natural loose dry avalanches on steep solar aspects where observed. Most size 1 with a few size 2. One very large loose dry was observed on a large south aspect feature Mount Kusam and was size 2.5 or greater.

Avalanche Problems

Persistent Slab

This problem has now become stubborn to triggering

Location: This problem is widespread, however isolated areas such as convex rolls and unsupported terrain is where it is most concerning.

Possibility: Triggering of this avalanche problem from light loads such as skiers are unlikely to possible. Natural avalanches are unlikely.

Size: If triggered, expect these avalanches to be large size 2 and will be big enough to bury, injure or kill a mountain traveler.

Wind Slab

This problem may be small but in isolated terrain with larger adjacent areas of fetch it is likely to be problematic. Expect forecast North winds to continue to transport available snow and over the forecast period, this problem will become larger in terms of destructive size.

Location: Specific to South aspects in areas lee of ridgetops.

Possibility: Triggering of this avalanche problem from light loads such as skiers is possible to likely. Natural avalanches are unlikely.

Size: If triggered, expect these avalanches to be small size 1 but in large terrain with available fetch zones to be large up to size 2.

Loose Dry

This problem is solar induced and in areas such as the other regions of the forecast areas , enough new snow exists for these avalanches to gain mass.

Location: Specific to Solar aspect terrain where loose and dry unconsolidated snow exists.

Possibility: Triggering of this avalanche problem from light loads such as skiers is possible to likely. Natural avalanches are unlikely.

Size: If triggered, expect these avalanches to be small size 1 but could gain mass and push a traveler into a terrain trap.

Snowpack Summary

Snowpack depths vary from 350 cm in norther regions to 500cm plus in the mid and southerly region of the forecast area. They do all have one similar characteristic and that is the January 23, 2021 PWL. This layer can be found between 60 and 100 cm deep and has been reactive to extensive testing. Moderate compression testing produces sudden planar results. This problematic condition, will continue to linger and should be monitored and observed prior to committing to entering terrain. Currently a well bonded layer dense snow is “bridging the upper snowpack” and protecting this layer from triggering in all but thin areas and unsupported features. Expect this to begin to strengthen with the coming cool weather.

Snowpack Details

Surfacevariety of surfaces, new low density snow, wind scoured at upper ridge tops and wind loaded on southerly aspects.
UpperA dense and strong layer of poly crystals overlies rounds.
MidAn eroding crust with facets at its base.
LowerWell settled.

Past Weather

Previous warm weather has been followed by cooling temperatures with freezing levels nearing seas level and moderate North west wind. The norther region of the forecast area ( north of sitika river) received 20 cms of new snow and this was found at 300m and above. During Saturday and Sunday, ridgetop wind transport was evident as available snow was at times being transported to south east aspects. Sun was in full effect during periods of clear skies, direct solar aspects became warm and numerous Loose dry avalanches ran naturally.

Weather Forecast

A strengthening artic high pressure is entering the region delivering to our forecast area, cool temperatures, clearing sky, and moderate to strong North West wind. The possibility of power flurries delivering daily light amounts of snow to isolated areas exists, this seems to be focused to the southern areas of our region. The outlook for the week indicates the possibility of widespread snow showers with amounts in the moderate range and snowfall to sea level.

Monday: No new precipitation, Winds Light to Moderate from the North West, Freezing levels at sea level with a day time a high of 500 meters.

Tuesday: 0-5 cm, Winds light from the South East, Freezing levels at sea level with a day time high of 600 meters.

Wednesday: 0-5 cm, Winds Moderate from the North East, Freezing levels at seas level with a daytime a high of 500 meters.

Posted on Monday February 8, 2021 by Jesse Percival

Past Bulletins