Avalanche Forecast

Moderate - Uncertainty is due to the timing, track, & intensity of the incoming weather system.

A cold front crossing the region on Sunday will bring some localized heavy accumulations.

SATURDAY NIGHT: Cloudy, 20-30 km/h west wind, treeline temperatures drop to -8 C.

SUNDAY: Snowfall picking up midday with 5-10 cm around Whistler by the late afternoon and 10-20 cm further south and west, 40-60 km/h south wind, treeline temperatures reach -5 C.

MONDAY: Another 10-20 cm of snow by the morning then sunny in the afternoon, light west wind during the day, treeline temperatures around -5 C.

TUESDAY: Mostly cloudy, 20-30 km/h southwest wind, treeline temperatures around -5 C.

Storm slabs were reactive to human and explosive triggering on Friday, producing numerous size 1-2 avalanches that were 30-60 cm thick. Preliminary reports from Saturday suggest the storm slabs were less reactive, but cornices remained easy to trigger with explosives. Looking forward, fresh storm slab avalanches will be likely later in the day on Sunday.

Prior to the storm, a few isolated large (size 3) avalanches were reported west of Hwy 99, and there is some uncertainty about whether they were just thick wind slabs or whether they also involved older weak layers in the snowpack. These appear to be anomalous events that were perhaps aggravated by warm temperatures last week.

New snow will accumulate throughout the day with 5-10 cm expected around Whistler and 10-20 cm further south and west. This will bring storm totals since Thursday to 40-60 cm, which sits above a melt-freeze crust up to roughly 1600 m and higher on sun-exposed slopes or dry snow on northerly aspects at high elevations.

Around 150 to 300 cm of consolidated snow may overly sugary faceted grains formed earlier this season. These layers are expected to be spotty around the region and we haven't received conclusive evidence of them being the culprit of any recent avalanches. That being said, it is possible they may be associated with a few large avalanches around the Whistler area last week.

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.

• Avoid freshly wind loaded terrain features.
• Watch for rapidly changing conditions during periods of heavy loading from new snow, wind, or rain.
• Use careful route-finding and stick to moderate slope angles with low consequences.
• Look for signs of instability: whumphing, hollow sounds, shooting cracks, and recent avalanches.
• Pay attention to cornices and give them a wide berth when traveling on or below ridges.