Archived

Avalanche Forecast

Mar 15th, 2019–Mar 16th, 2019

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

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

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

2: Moderate

The avalanche danger rating below treeline will be moderate

Regions: Kootenay Boundary.

As temperatures continue to warm, pay particular attention to slopes that are being affected by the sun.

Confidence

Moderate - Timing or intensity of solar radiation is uncertain

Weather Forecast

FRIDAY NIGHT: Cloudy with clear periods. Alpine low temperature -5C. Light west winds at ridgetops.SATURDAY: Cloudy with sunny periods. Alpine temperature reaching -2C. Light west winds at ridgetops. Freezing level between 1800m - 2000m.SUNDAY: Mix of sun and clouds. Alpine temperature around 0C. Light west winds at ridgetops. Freezing level between 2000m - 2300m. No overnight freeze expected.MONDAY: Mainly sunny. Alpine high temperature +4C.Light west winds at ridgetops. Freezing level between 2500m - 2800m. No overnight freeze expected.

Avalanche Summary

Numerous small (up to size 1.5) wind slabs were triggered by skiers on Thursday on various lee aspects at treeline and above. The sun has already affected the snow on steep south-facing slopes and triggered small loose wet avalanches at lower elevations. Natural and human triggered loose wet avalanches are likely with tomorrow's strong sun and steadily rising freezing level.

Snowpack Summary

In the last week 25-40 cm of storm snow has fallen which is becoming moist on aspects that have seen the strong March sun. Recent winds have switched from north to west to south leaving wind affected snow on a variety of aspects, especially on features near ridgetops and open areas at treeline. Various surfaces are hidden under the recent storm snow such as sun crusts on southerly slopes, hard wind-affected snow in exposed locations and soft faceted snow in sheltered areas.Two weak layers that mainly consist of surface hoar are buried in the snowpack between 55 and 90 cm deep, these were buried in mid-February and early-February. The layers may be associated with a melt-freeze crust on southerly aspects. Although no recent avalanche activity has been reported on these layers, they may become a concern as the warming progresses.

Avalanche Problems

Wind Slabs

Wind slabs will remain reactive, particularly on south-facing slopes that are affected by the sun.

Be careful with wind loaded pockets, particularly near ridge crests and roll-overs.Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.The best powder will be found in sheltered locations on northerly slopes.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 2

Loose Wet

The recent snow will quickly get destabilized as the sun affects it for the first time. This problem will likely be encountered in the afternoon hours.

Use caution on sunny steep slopes, if the snow becomes moist or wet.Rock outcrops will heat faster with the strong March sun.Loose wet sluffs may begin small but can grow big and push you into dangerous terrain

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

Elevations: All elevations.

Likelihood: Possible - Likely

Expected Size: 1 - 1.5