Avalanche Forecast

Issued: Apr 2nd, 2014 9:32AM

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

ghelgeson, Avalanche Canada

Northwest Inland.

Avalanche hazard will likely increase throughout the day, be sure your plans allow for a safe retreat from the mountains.

Summary

Confidence

Fair - Timing, track, or intensity of incoming weather system is uncertain

Weather Forecast

Synopsis: A series of relatively weak systems should deliver daily precipitation through the weekend. There is potential for a very potent storm early next week, but its still way too early to count on.Wednesday Night: Precipitation: 2:7mm - 3:10cmThursday: Freezing Level: 700m - 1100m; Precipitation: 2:10mm - 2:15cm; Wind: Treeline: Moderate, S/SW | Ridgetop: Strong, SWFriday: Freezing Level: 800 - 1200m Precipitation: Trace; Wind: Treeline: Light, SW | Ridgetop: Moderate, WSaturday: Freezing Level: 1100m - 1400m; Precipitation: 1:8mm - 2:13; Wind: Treeline: Light, S | Ridgetop: Strong, SW

Avalanche Summary

A steep rocky NE facing feature at 1900m released naturally resulting in a size 3 avalanche. Some natural cornice falls were reported, but they did not trigger slab avalanches on the slopes below.

Snowpack Summary

It's starting to feel like spring in the NW. Valley temps are creeping into the double digits during the day, and there are reports of the top 15 cm of the snowpack becoming moist during daytime heating.The last significant shot of snow was on March 27th, 10 - 15 fell on March 30th. This new snow rests on top of a haggard old surface composed of old wind slab, melt freeze crust, and faceted old snow. Ongoing melt freeze cycles will likely help to heal any surface instabilities.The early March layer found in the upper snowpack is composed of facets/surface hoar on shady aspects and facets/crust on southerly aspects. I suspect this layer has been the culprit in the human triggered avalanches from March 27/28 in the neighboring NW Coastal region, that are being reported on the Balktalk Facebook Page.The early February crust/facet/surface hoar combo can be found deep in the snowpack, although I suspect it's gone dormant for now.

Problems

Storm Slabs

New snow accompanied by strong wind should result in new slabs being formed on top of surface hoar and crusts beginning Wednesday night. I expect these touchy slabs will become more and more problematic as the day goes on Thursday.

Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.>Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.>Minimize exposure to overhead avalanche terrain, large avalanches may reach run out zones.>Stick to simple terrain and be aware of what is above you at all times.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 4

Deep Persistent Slabs

Two buried weak layers exist in the snowpack. These weak layers could be activated by cornice fall, a smaller surface avalanche in motion, or a rider finding the sweet spot, which would be most likely in steep rocky terrain.

Be aware of the potential for large, deep avalanches due to the presence of buried facets and surface hoar.>Extra caution needed around cornices with current conditions.>Be aware of thin areas that may propogate to deeper instabilites.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

3 - 7

Valid until: Apr 3rd, 2014 2:00PM