Archived

Avalanche Forecast

Mar 27th, 2021–Mar 28th, 2021

Alpine

4: High

The avalanche danger rating in the alpine will be high

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

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

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

Regions: Sea To Sky.

There is uncertainty with forecast precipitation amounts Saturday night through Sunday. If snowfall amounts materialize as forecast, then the avalanche danger will certainly be High.

Confidence

Low - Forecast precipitation (either snow or rain) amounts are uncertain.

Weather Forecast

SATURDAY Night: Snow, accumulation 10-25 cm, moderate to strong southwest wind, treeline temperature around -4 C, freezing level 1100 m.

SUNDAY: Snow, accumulation 15-30 cm, moderate to strong southwest wind, treeline temperatures around -5 C, freezing level 1000 m.

MONDAY: Mix of sun and cloud, light northwest wind, treeline temperatures around -5 C, freezing level 1000 m.

TUESDAY: Mix of sun and cloud, light west wind, treeline temperatures around -3 C, freezing level 1100 m.

Avalanche Summary

A few cornices were triggered naturally and from explosives on Tuesday, Wednesday, Thursday and Friday. They were very large, as is expected at this time of year. Expect to see an increase in storm and wind slab avalanches on Sunday as new snow accumulates and the wind blows strong from the southwest.Â

Snowpack Summary

Another 15-25 cm of new snow may have fallen Saturday night. This sits above a widespread melt freeze crust, with the exception of high north-facing terrain. It may also be sitting on small surface hoar crystals reported on north and east aspects in the alpine.

Remember that cornices along ridgelines are large at this time of year and always have the possibility of failing naturally or from the weight of a human.

Terrain and Travel

Minimize exposure during periods of heavy loading from new snow, wind or rain.
Storm slab size and sensitivity to triggering will likely increase through the day.
Pay attention to cornices and give them a wide berth when traveling on or below ridges.

Avalanche Problems

Storm Slabs

The forecast calls for heavy snowfall combined with moderate to strong southwest wind Saturday night through Sunday. This will promote storm and wind slab formation at upper elevations.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Likely - Very Likely

Expected Size: 1 - 2

Loose Wet

Rain at lower elevations may weaken surface snow and cause it to sluff in steep terrain

Aspects: All aspects.

Elevations: Below Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 1.5