Turnagain Pass Avalanche Forecast

Another shot of snow and wind has moved in overnight covering the clear skies and great riding and skiing conditions that many folks found yesterday. This new system is taking center stage but we did get some great footage of the natural cycle that occurred 2 days ago in the Valentine’s Day storm snow. Check out the many observations/photos sent in on our observations page.

By 6AM this morning we have picked up 3-4” of low density snow and another 5-10” is forecast to be on the way. This is coming in with strong east winds and slightly warming temperatures. Storm snow avalanches will be our primary concerns. These include shallow storm slabs, larger wind slabs and fast running loose snow sluffs.

Wind slabs will be the most concerning and likely to be fairly sensitive to human triggers as they are sitting on colder weaker snow. There is ample existing snow available for transport (yesterday’s cold powder) to build 1-2′ think slabs even if new snow amounts are less than expected. Near and above treeline elevations began seeing wind transport yesterday afternoon and these have only grown as winds have increased since then. Watching for areas with stiffer wind deposited snow and cracking in the new snow around you will be clues you have found a slab. These are most likely to be found on rollovers, off ridgelines and in cross-loaded gullies.

Below is a photo from yesterday’s east wind hitting Grand Daddy Peak producing a plume blowing snow low onto its western face.

Below treeline: Keep an eye out for winds to penetrate below treeline and build shallow touchy wind slabs. Loose snow sluffing on slopes steep and long enough will also be likely as this storm is colder with snow to sea level.

We continue to find a variable and concerning mid-pack snow structure at the mid elevations between 1,500’ and 2,800’. This is more pronounced in the Girdwood Valley. Buried 2-4’ deep now is a thin layer of weak snow sitting on a crust formed in late January. We have yet to see any avalanche activity on this crust in the Turnagain area but there has been some in the Girdwood Valley during the past week. Our pits are telling us this interface is fairly hard to trigger but it is present in the Pass. As more snow loads slopes with additional weight the potential exists for a deeper and more dangerous avalanches to occur at mid-elevations. If you haven’t already done so, check out Graham’s video from yesterday.