Hatcher Pass

Yesterday our forecast team observed some isolated wet loose activity on Microdot, likely naturally triggered from solar warming during the day on Tuesday. 

Loose wet avalanche coming out of the rocks on Microdot from Tuesday.

We were able to kick off some small wind loaded pockets isolated to the ridgeline on our way up 4600’ yesterday. This instability is more indicative of recent activity which is becoming more difficult to find.

Cracking and some reactivity observed isolated to the ridgeline. 4k ft E/SE facing.

Relatively few parties have been out over the last few days, limiting observations. If you’re out and about this weekend let us know what you see!

A few sunny days and a couple inches of recent snow have improved riding conditions significantly. Soft, supportable turns are easy to find on the north half of the compass. While some southerly facing slopes have picked up a crust and were exposed to more recent periods of wind, skiing in these locations can still be smooth, edgeable, and enjoyable. 

Good coverage and quality conditions will be found this weekend.

A persistent slab hazard exists on all aspects, generally on slopes steeper than 35°, where it’s possible to trigger an avalanche 4-12’’ deep on a number of previously buried weak layers of snow. Below we break down the problem on shady versus sunny aspects. 

There’s no denying that the snowpack at Hatcher Pass is relatively thin. With a thin snowpack comes strong temperature gradients and faceted snow. Over the course of the season periods of wind, sun, and warm temperatures have formed crusts that are now buried throughout the snowpack. These crusts help concentrate the temperature gradient and drive faceting around these layers. This might sound complicated but we’ll explain what it means for you here. 

On the north half of the compass the biggest hazard is still triggering a lingering weak layer of graupel that fell with last week’s snow. Less likely but still possible is triggering an avalanche on a slightly deeper layer buried under some of the wind slabs that formed earlier in the month. These avalanches would be generally 6-12 inches deep and 30-50 feet wide and most likely found on windloaded, convex, northerly facing slopes. 

On southerly aspects the snowpack is drastically different but the problem is similar. Here the snowpack is layered with a myriad of crusts that formed from rain events, temperature inversions, and the increasingly strong sun. Snowpit tests in these locations revealed there is a possibility of triggering an avalanche on a faceted layer of snow between two of these crusts about 12’’ down. While we haven’t seen much activity that relates to this problem directly, the structure and strength of the snowpack indicate it could be an issue. Additionally, periods of sun and warm temperatures have and will continue to make a more cohesive slab which increases the likelihood of triggering a slide. 

The layered cake that is the south facing snowpack.

If that sounds like a lot, don’t worry. This problem should be relatively manageable with safe travel etiquette and appropriate terrain choices. Ski one at a time, and if the slope you’re on is getting warm, move to cooler aspects. 

Warm temps and full sun will initiate wet loose activity on steep solar aspects. This activity could start as rollerballs and pinwheels but easily fan out and gouge into older, deeper layers of the snow as it moves down the hill. 

It’s looking like a beautiful weekend with partly cloudy skies and temps in the mid to upper 20’s. The sun is starting to get higher and gain strength rapidly. 25° can feel like 55° on a sunny day and any slopes exposed to the direct sun could become unstable with the warming. Luckily, overnight temps have and look to remain cool which will limit this activity but also lead to frozen surfaces on steep southerly slopes. 

The problem with wet loose activity is that it can entrain so much snow as it moves down the slope that a slide that starts out from a small rollerball can easily become large enough to bury, injure, or kill. Avoid sunny slopes during the heat of the day and if the slope you’re on is getting warm, sticky, or unsupportable consider changing aspects.