January 30, 2015

Backcountry Snow, Weather, and Avalanche Conditions for Gulmarg 30.1.2015

BELOW TREELINE Below 3,000m – LOW

DangerScale_Icons
Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.

 

ALPINE 3,000 to 4,000m – CONSIDERABLE

Dangerous avalanche conditions. Careful snowpack evaluation, cautious route-finding, and conservative decision-making essential.

 

Primary Problem

Untitled6A persistent slab is any slab formed over a persistent weak layer, in our case, depth hoar. These slabs are hard to predict, often are triggered from the middle or low on the slab, and can propagate over large areas and across terrain features traditionally thought of as safe zones, like ridges, benches, and low angle terrain. The problem can last for weeks or months.

Secondary Problem

wind-slabWind slabs form where wind has deposited or drifted snow. You will find them on lee aspects, generally near ridge lines, around terrain features and in ‘cross-loaded’ features like vertical ridges, couloirs and gullies. Wind slabs may remain reactive for up to a week after the wind event has ended.

Untitled2 copySnowpack discussion

I am keeping the danger rating at considerable for the alpine, and low below tree line again today. A better word for considerable is serious. We have serious avalanche danger in the alpine right now.

Persistent slab is the problem. Our current snowpack is >100cms, with 30-50 cms of depth hoar on the bottom, and ~80cm slab on top of that. Likely places for triggering avalanches are under rocks, or near shallow snow areas on N,NE, and E facing slopes . Travel above tree line today is dangerous. Recent winds also deposited deep wind slabs near ridgelines on leeward slopes that still have the potential to run on the old wind-hardened snow surface.   During control work yesterday we ski cut a 80 cm thick wind slab on an E facing slope that ran most of its path. We also rattled loose a D3-sized avalanche on a NE facing slope that ran most of its path. These avalanches were in areas that receive regular avalanche control work.

Studies have shown that the most common danger rating for avalanche fatalities to occur is with a considerable rating. Treat the word considerable with respect. The coming storm will hopefully provide a much-needed natural avalanche cycle for our tender snowpack.

Untitled3Weather Discussion for 3000m Mostly clear skies today with minimal winds forecasted. Significant snowfall is forecasted for the end of the coming weekend.

beaconBeacon, Shovel, and Probe required to access phase 2 of Gulmarg gondola.