Avalanche Forecast

Issued: Feb 6th, 2015 9:10AM

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

ghelgeson, Avalanche Canada

Northwest Inland.

There's fresh snow and clearing skies in store for the weekend which sounds amazing, but we need to SLOW IT WAY DOWN and stick to conservative terrain as the snowpack adjusts to the recent load.

Summary

Confidence

Poor - Due to the number of field observations

Weather Forecast

Snowfall should slowly taper overnight. I'm expecting 5 to 20cm out of this last push. Winds should ease back (slightly), but I'm still expecting strong SW winds in the alpine Saturday. No snowfall is expected on Saturday, Sunday or Monday. Looks like it goes clear and dry through at least Tuesday.

Avalanche Summary

With the intense storm obscuring views, observations have been limited. I expect there is a widespread natural avalanche cycle occurring, we'll probably learn more about it as skies clear this weekend.

Snowpack Summary

The storm has produced approximately 20 to 50 cm of new snow accompanied by strong to extreme winds out of the E through SE. There are a number of weak layers in our snowpack, this storm should be a good test for all of them. In places the new storm snow sits on the early February surface hoar, little is known about the distribution of this interface. The late January crust is probably down 60 to 100cm in the south, it's likely shallower in the north. The mid-January rain crust(with some spatially spotty surface hoar on top) is down over a meter. It might still be a problem in thin snowpack areas. The crust/facet combination from November can be found near the ground. It's not an easy snowpack to work with, we'd greatly appreciate your observations via the Mountain Information Network.

Problems

Storm Slabs

Snowfall should taper before dawn Saturday morning, but I suspect there is still potential for natural avalanche activity Saturday as a strong SW wind blows and the snowpack adjusts to the new load.

Storm slab avalanches in motion have the potential to step down resulting in large avalanches.>Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.>Avoid all avalanche terrain during periods of heavy loading from strong winds.>Choose well supported mellow terrain.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

2 - 7

Deep Persistent Slabs

There's a lot of uncertainty surrounding the deeply buried weak layers in the snowpack. This weekend I would make decisions based on the assumption that every slope above treeline has the potential to produce a very large and destructive avalanche.

Be aware of the potential for large, deep avalanches due to the presence of buried crusts and/or surface hoar.>Avoid thin and/or rocky slopes where you're more likely to initiate an avalanche failing on deeply buried weak layers.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

4 - 7

Valid until: Feb 7th, 2015 2:00PM