Avalog Join
Archived

Avalanche Forecast

Apr 2nd, 2018–Apr 3rd, 2018
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
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
2: Moderate
The avalanche danger rating at treeline will be moderate
Below Treeline
1: Low
The avalanche danger rating below treeline will be low
Alpine
3: Considerable
The avalanche danger rating in the alpine will be considerable
Treeline
3: Considerable
The avalanche danger rating at treeline will be considerable
Below Treeline
3: Considerable
The avalanche danger rating below treeline will be considerable

Regions: Sea To Sky.

Surface snow conditions are extremely variable. Be alert for rapid changes under your skis or sled, and watch for fresh pockets of wind slab.

Confidence

Moderate - Intensity of incoming weather systems is uncertain on Tuesday

Weather Forecast

Unsettled weather until the next system arrives on Wednesday. Freezing levels will increase slowly & steadily.TUESDAY: Cloudy with flurries Monday overnight and into the morning (3-6 cm possible) / Light to moderate south west wind / Alpine temperature -7 / Freezing level 1000m WEDNESDAY: Snow (5-10 cm) / Moderate south west wind / Alpine temperature -4 / Freezing level 1300m THURSDAY: Snow (15-25cm) / Light to moderate southwest wind / Alpine temperature -3 / Freezing level 1600m

Avalanche Summary

On Monday, explosives control work triggered only a few size 1 wind slab avalanches in isolated terrain up in the alpine. On Friday a sled-triggered size 2 wind slab was reported near Grizzly Lake near Powder Mountain, on a north west aspect near 1750m. See the MIN post for more details. On Thursday several natural avalanches to size 2.5 were reported in the Tantalus Range. See the MCR for more details. On Wednesday there was a size 1 avalanche that sympathetically triggered a size 3 persistent slab avalanche resulting in a fatality. This was on a northeast aspect at 2000m, 50cm deep. Additionally there were reports of natural persistent slab avalanches size 2.5-3 on southeast through northeast aspects between 1800 and 2000m. These were reported to have happened in the previous 24-48 hours. See this MIN post for similar details.

Snowpack Summary

5-10 cm of new snow fell on Easter Sunday (with some locally higher amounts due to intense convective activity and gusty winds). Winds have been gusting strong, previously from the south and most recently the north.The end result is that snow conditions are wildly variable, ranging from melt freeze crusts on sunny aspects to scoured old hard wind slabs to isolated pockets of soft wind slab. See this MIN post for a good summary of conditions beyond the musical bumps. Old snow from a week ago rests on the March 21st interface, which has a very patchy distribution: moist grains at low elevations, crusts on solar aspects at all elevations and surface hoar/facets on north/east facing features at treeline and alpine elevations. Some west facing features may have surface hoar on top of a crust. The March 21st interface has been giving variably moderate to hard sudden planar results, typically down 50-60cm on 1-2mm facets.The mid and lower snowpack are strong and well settled.

Avalanche Problems

Wind Slabs

Recent strong north winds have formed wind slabs on southerly features near ridge crests. These could be most reactive where they may be sitting on firm, scoured snow or hard melt-freeze crusts.
Extra caution needed around cornices with current conditions.Use ridges or ribs to avoid pockets of wind loaded snow.Snow conditions may change drastically over short distances - be alert to changing surfaces.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 2

Persistent Slabs

A weak layer of surface hoar or facetted crystals has become reactive especially where it may be sitting on a hard crust.
Be aware of the potential for wide propagations.Avoid steep convexities or areas with a thin or variable snowpack.

Aspects: North, North East, East, South East, South, South West.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 3