Avalanche Forecast

Issued: Nov 25th, 2017 4:17PM

The alpine rating is moderate, the treeline rating is low, and the below treeline rating is low. Known problems include Loose Wet.

Avalanche Canada mgrist, Avalanche Canada

If the rain-soaked snow freezes as expected on the weekend, avalanche hazard will follow a decreasing trend until more snow falls late Sunday. Please treat this forecast as an initial assessment, as we have little information at this time.

Summary

Confidence

Moderate - Due to the number of field observations

Weather Forecast

We're looking at relatively benign weather until Sunday afternoon, when a brief but intense cold front will bring 10-15 mm of rain and then 10-20 cm of snow by Sunday night. Sunday: 10-15mm of rain early afternoon changing to snow (10-20 cm possible overnight). Freezing levels 2200m decreasing to surface by the evening. Winds moderate from the south west. Monday: Scattered flurries. Freezing level around 1200 m. Moderate westerly winds.Tuesday: Isolated flurries. Freezing levels rising to 1700 m. Moderate southwesterly winds.

Avalanche Summary

Several loose wet avalanches to Size 3 (some digging to ground) were reported at the end of the rain event. Whether avalanches are still running is a different question and unfortunately the weather and lack of observers is making that hard to determine. I'd expect a decrease in avalanche activity with cooling temperatures on the weekend.

Snowpack Summary

The tropical punch during the week dropped upwards of 80mm rain (that's over 3 inches!) and resulted in a widespread wet upper snowpack. The freezing level rose to close to 3000 m on Wednesday and Thursday meaning very few places, if any, will have escaped the melt. Cooling temperatures after the rain resulted in widespread crusts which may break down with daytime warming.During the week, the snowpack also diminished by 20-40 cm. Below treeline snowpacks are at or below threshold and travel in this elevation band is rugged. Expect treeline snow depths of around 60 cm. A crust that formed around Halloween has been reported from neighboring regions and may still exist in the Lizard-Flathead region too, roughly 40 cm below the surface.

Problems

Loose Wet

An icon showing Loose Wet
Daytime warming may break down the rain crust which formed after the monsoon last week. If you're easily breaking through the crust or are traveling in soft mushy snow, loose wet avalanches are possible.
Conditions are improving, but be mindful in areas that still have soft mushy snow.Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Valid until: Nov 26th, 2017 2:00PM