Avalanche Forecast

Issued: Feb 14th, 2015 4:00PM

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

a.l. horton, Parks Canada

Jasper.

http://www.pc.gc.ca/apps/scond/Cond_E.asp?oID=19299&oPark=100092We have a very touchy avalanche conditions and have seen some very large full path avalanches in the last 24 hrs. Stick to low angle terrain away from large overhead slopes.

Summary

Weather Forecast

Daytime temperatures will cool on Sunday with good overnight freezes possible by Monday. Dry sunny conditions are forecast into the week. Light SW winds will accompany these stable conditions.

Snowpack Summary

Heavy rain that changed to snow overnight has created a saturated snowpack extending into tree line. Limited overnight freeze created a weak melt freeze crust that broke down quickly with daytime heating and solar radiation. At higher elevations, a 40-80 cm deep persistent slab is sitting over multiple touchy interfaces on all aspects.

Avalanche Summary

There has been an avalanche cycle with numerous size 2 slab avalanches ranging form 1700 m to 2600 m on all aspects, many stepping down to the basal facets/November rain crust. Several larger avalanches also observed including a full path size 3.5 on the South Churchill Slide path (East Aspect 2400 m)

Confidence

The weather pattern is stable on Sunday

Problems

Persistent Slabs

Forecasters are doubtful that cooler temperatures will improve this weakness in the short term. Triggering of these slabs is possible even in low angle terrain .

Minimize exposure to sun exposed slopes when the solar radiation is strong.Use conservative route selection, choose moderate angled and supported terrain with low consequence.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 3

Deep Persistent Slabs

This layer has become more reactive with recent weather. Even light loads are enough to trigger full depth avalanches.

Be aware of the potential for full depth avalanches due to deeply buried weak layers.Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 4

Valid until: Feb 15th, 2015 4:00PM