Avalanche Forecast

Issued: Jan 23rd, 2018 4:00PM

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

deryl kelly, Parks Canada

Jasper.

A persistent problem in the snow pack, makes up the top 30 to 50cm. Field teams have been monitoring the changing sensitivity of these layers carefully, as should you!

Summary

Weather Forecast

A strong SW flow with a series of low pressure storm cells tracking west from BC will continue bringing unsettled weather and light snow through the week for a forecasted total of 20 cm. Wednesday, expect as much as 10cm overnight the through the morning Thursday.Â Alpine High -6C. Ridge wind light to moderate SW, gusting to moderate values.

Snowpack Summary

Windslab continues to build in open areas and has covered two surface hoar layers in the top 30 to 50cm of the snowpack. The distribution of this SH in the terrain has been found in immediate lees of wind swept features, around TL and into the alpine. Field teams will continue to monitor the sensitivity of these layers carefully, as should you!

Avalanche Summary

Natural avalanches up to size 1.5 were observed Tuesday in windswept alpine moraine features. Appears to be running on the persistent slab interface dow 30 to 50cm.

Confidence

Intensity of incoming weather systems is uncertain on Wednesday

Problems

Persistent Slabs

This problem slab is made up of 3 significant interfaces. From top down, Jan 18 FC, dwn 15cm. Jan 7 FC/SH, dwn 20, and finally the Dec 18th interface 30 to 50cm down. All interfaces seem to be slowly healing but, inconsistent sensitivity to triggers.

Watch for whumpfing, hollow sounds, and shooting cracks.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 2.5

Wind Slabs

Small inputs of fresh storm snow with southwesterly winds continue to build small lenses of windslab in sheltered lee features at ridge crests.

Be careful with wind loaded pockets while approaching and climbing ice routes.Be cautious as you transition into wind affected terrain.

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

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Valid until: Jan 24th, 2018 4:00PM