Avalanche Forecast

Issued: Mar 28th, 2021 8:06AM

The alpine rating is high, the treeline rating is high, and the below treeline rating is considerable. Known problems include Storm Slabs, Cornices and Persistent Slabs.

jonas hoke,

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The storm is here!

Avoid overhead hazard today, natural avalanches have already been running well into run out zones.

Summary

Weather Forecast

A cold front passes our area today, temps cool significantly in its wake.

Today: 15-20cm of snow. Alpine High -3 C. Ridgetop wind mod-extreme SW. Freezing level (Fzl) 1600m

Tonight: Flurries (5cm). Low -14. Moderate SW wind.

Monday: Sun and cloud mix. High -12. Moderate W wind. Fzl valley bottom.

Tuesday: Isolated flurries. Low -14, High -7. Fzl 1100m

Snowpack Summary

Ongoing snowfall and wind (up to 35cm in the past 48hr) has created reactive slabs, and added significant growth to cornices. Snowfall totals of up to 75cm over the March 18th interface (this has been reactive just West of the park, on sheltered North aspects where it is surface hoar). The mid and lower snowpack is settled and strong.

Avalanche Summary

Several large (up to size 3.0) natural avalanches have occurred in the highway corridor overnight from all aspects.

On Saturday a field team triggered a small (size 1.5) windslab in a northerly lee at Treeline.

A couple of natural cornice falls were observed on Saturday, one triggered a slab producing a large avalanche that ran to valley bottom.

Confidence

Problems

Storm Slabs

An icon showing Storm Slabs

Warms temps, wind and heavy snowfall are the perfect recipe for storm slab development.

  • Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Very Likely

Expected Size

1.5 - 3.5

Cornices

An icon showing Cornices

Cornices are huge and expected to fail naturally with snowfall and wind today.

  • Avoid travel on slopes that are exposed to cornices overhead.

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

Elevations: Alpine.

Likelihood

Likely - Very Likely

Expected Size

1 - 3

Persistent Slabs

An icon showing Persistent Slabs

The March 18th persistent weak layer is buried approximately 60-80cm deep as surface hoar in sheltered areas around treeline, and a suncrust on solar aspects.

  • Pay attention to overhead hazards like cornices which could trigger the persistent slab.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1.5 - 3.5

Valid until: Mar 29th, 2021 8:00AM