Turnagain Pass Avalanche Forecast

There were a couple very small skier triggered wind slab avalanches yesterday on freshly wind loaded rollovers/wind lips near treeline. One natural wind slab, a bit bigger (30-40’ across, ~1′ deep and running around 150’), was seen in a cross-loaded gully on the east face of Seattle Ridge (looker’s left of the motorized “up-track”). Keep in mind, the low visibility kept folks to the mid and lower elevations leaving the upper, and more concerning, slopes untouched.

Today, triggering a lingering wind slab will be the primany concern. The wind has backed off considerably this morning but it did load its fair share of slopes over the past several days. These slabs are most likely to be 1-2 feet in depth and found just off ridgelines, rollovers and cross-loaded in gullies. Watching for smooth “pillowy” surfaces, hollow feeling snow and cracking in the snow around you will be keys to recognizing these slabs. With the potential for good visibility today and travel to steeper slopes, even a small avalanche triggered can be dangerous if one gets washed into a terrain trap (i.e., over a cliff or into a gully).

Cornices:  With several days now of warm temperatures, snow and wind, cornices have been building. Giving these monsters a wide berth will be prudent as they could be close to the tipping point.

Below treeline:  It will be unlikely to trigger an avalanche below treeline. A few inches of low density snow sits on multiple crust layers that extend up to 2,000’-2,500’. The most recent crust was formed February 2^nd and is somewhat breakable with a stouter rain crust from 1/30 below.

Ah, the deep slab problem… Yes, it has been 3 weeks now since the last deep slab avalanche and yes, it would be nice to put this broken record away, but time will tell. We have been tracking the weak October and November facets at different elevation bands the past couple days. These are buried 4-7’ deep in general and continue to show gains in strength. Reports from the 2,400′ and 3,000’ band show the facets remain dry and intact but are rounding, bonding and gaining in hardness. This is all good news and what we want – but these pits are only small snapshots. Due to the severity of this type of avalanche, and the rule that facets can come back to bite one, it is a guilty untill proven innocent situation. In the mean time, steering clear of thin spots, exposing only one person at a time and moving efficiently through avalanche terrain are good practices.