Turnagain Pass

No avalanches have been seen or triggered in the last several days in our forecast zone or close to it. Last Saturday, there was a large wind slab triggered by a snowmachiner in the Whittier area. The last known deep slab avalanche was remotely triggered from above by a skier just northeast of Girdwood. Before that slide, 18 very large human-triggered avalanches occurred that were between 3-6′ deep. All of these we suspect failed on faceted snow that was buried on March 14th. There has been relatively little traffic in the forecast zone the past week.

With a relatively warm night, a dusting of new snow, and the chance for sunshine and warm temperatures late in the afternoon and evening today, the surface crusts could melt enough to create a wet loose avalanche problem. Slopes facing the sun with rocks and vegetation, like the photo below, will be first to heat up. If you happen to be out during the ‘heat’ of the day, keep an eye on how wet and saturated the snow is becoming. If your boot/skis/board are sinking into gloppy wet snow, that’s when we don’t want to be on anything steep. These wet sluffs could be small and harmless, but can also entrain quite a bit of snow and become more dangerous.

Example of your classic springtime wet loose avalanche. This one is on the westerly aspect of Bird Ridge and occurred naturally last Sunday, April 2nd. Seen from the Seward Highway and photo taken by Paul Wunnicke on 4.3.23.

Someone triggering a very large deep slab avalanche is still a concern. It has been just over a week since the last one of these occurred. The problem ‘weak layer’ is old faceted snow that sits under all the March storm snow. This weak layer is roughly 3-6′ deep in the snowpack. Unfortunately, time can make this type of avalanche less likely, but the consequences if someone hits just the wrong spot can be deadly. This is the ‘scary MODERATE’ phase of Deep Persistent Slab avalanches. As we’ve been saying it’s a really tricky situation. Slopes can seem just fine, yet there is a small chance a slab can release that propagates across an entire bowl and runs through low angle terrain.

Yesterday we took at look at the SE face of Seattle Ridge where we have not seen any large slabs occur; specifically the Repeat Offender path above the motorized up-track. This was the first pit we have dug where we didn’t find an obvious weak layer. This is good news, yet we can’t hang our hat on one data point. All in all, this problem will finish the season with us and could cause large wet slabs when the snowpack really starts warming up. For the time being, this setup is still keeping us mostly traveling in the lower angle terrain with a conservative mindset.

If you are headed up ridges and into Alpine, lingering wind slabs may be found from the easterly winds on Monday and Tuesday. These are likely to be in the typical places where the east winds drift snow off ridgelines and in cross-loaded gullies. They are likely to be in the foot deep range. It’s also that time of year cornices can start becoming more unstable. As always give these a very wide berth.