Avalanche Forecast

Issued: Feb 9th, 2019 8:00AM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is moderate. Known problems include Wind Slabs and Persistent Slabs.

Parks Canada andrew jones, Parks Canada

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http://www.pc.gc.ca/apps/links/goto_e.asp?destination=http://data.avalanche.ca/Images/SPAW%20Feb%207%202019.pdfCold related injuries are a real possibility today. Pay special attention to new wind slab development on southerly aspects in the alpine, and buried surface hoar below treeline.

Summary

Weather Forecast

Cold temperatures will persist into the foreseeable future. Sunny today with no signs of precipitation. The alpine temperature will climb to -20, although it is presently -26 at 2000m. Ridge winds from the E, 20 km/h. There is a real risk of cold related injuries such as frostbite.

Snowpack Summary

Strong to extreme north winds created wind slabs and loaded pockets on lee features. Wind slabs sit atop a crust on steep solar aspects in the alpine. Cold temperatures are promoting near surface faceting. The storm snow has settled to ~50cm. The Jan 31 and Jan 17 interfaces (surface hoar and sun crust) are down ~50cm and ~70cm at tree line.

Avalanche Summary

No new avalanches were observed yesterday.

Confidence

Wind effect is extremely variable

Problems

Wind Slabs

An icon showing Wind Slabs
Strong to extreme NE winds have redistributed storm snow into hard wind slabs and loaded pockets on lee features. On southerly aspects, wind slabs are poorly bonded to a buried crust. These slabs can create large avalanches with wide propagations.
Be cautious as you transition into wind affected terrain.If triggered the wind slabs may step down to deeper layers resulting in large avalanches.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2.5

Persistent Slabs

An icon showing Persistent Slabs
The Jan 31 and Jan 17 surface hoar layers are down ~50 and ~70cm respectively. This layer exists on all aspects, and is most problematic between 1400-1900m and on steep solar aspects where it overlies a crust.
Caution on open slopes and convex rolls at treeline and below, buried surface hoar may be preserved.

Aspects: All aspects.

Elevations: Treeline, Below Treeline.

Likelihood

Possible

Expected Size

2 - 3

Valid until: Feb 10th, 2019 8:00AM