Avalanche Outlook

[Toast]

I was out this weekend playing in the snow on the north facing aspects around Yodelin. I felt probably a dozen distinct whumps in the snow. The best I can describe that sensation is the Surround Sound effects of the T-Rex coming during Jurassic Park. It was really eerie. We skied well in the trees an over less exposed terrain.

 

There's about 3 feet of unconsolidated powder covering a 1" plate of ice with a very well bonded crystal structure. Grabbing a piece, I broke off a saucer sized chunk of ice. Beneath that was more unconsolidated snow. This layer was what was breaking about 20' around us as we walked along the trail. If we were on a steep slope, that whole sheet would slide. I didn't have a loop to look at the snow structure on top and below, but friends said they found a sliding layer above. I thought there may be TG snow below.

 

If memory serves me right, this is similar to the snow pack that formed three years ago when we had a whole bunch of avalanche fatalities, most notably up in Canada. There was a long stint of no snow (forming a hard well bonded layer) then a huge dump of freshies on top. Whatever the case, the hard plate I found may persist a long time and be a ticking time bomb later in the season.

 

I'd be interested in hearing a snow science discussion among those digging pits.

[Cobra_Commander]

Generally we get so much snow here, and it is so moist, that the next storms will simply crush any instability deep in the pack. Generally. Certainly, north-facing protected aspects can maintain instability for some time.

[Billygoat]

A little surface slough I set off on a 40+ degree, North facing slope below Heliotrope Ridge Sunday Dec 4.

 

 

 

 

We found the conditions there to be really stable and bonded to the old freeze/melt layer. The snowpack really thin in places and filled in with powder elsewhere. As the day wore on tho, it kept snowing and the wind (from the West) transported snow was becoming packed and crusty.

[Toast]

Generally we get so much snow here, and it is so moist, that the next storms will simply crush any instability deep in the pack. Generally. Certainly, north-facing protected aspects can maintain instability for some time.

 

In general I'd say you're right, but I'm guessing that there's an abnormal snow pack setting up. There's a thick insulating layer atop a really strong ice layer that's probably not going to break down or morph anytime soon. That will protect the weak layer beneath which may grow more granular and even weaker over time due to temperature gradient.

 

I dunno, I'm a novice with regard to snow science, but I'd like to hear what others think.

[cj001f]

There's a thick insulating layer atop a really strong ice layer that's probably not going to break down or morph anytime soon.

What for the inevitable warming cycle

[Dru]

Oh man, if the avvy hazard gets high, you might have to break down and go iceclimbing

[Cobra_Commander]

maybe some laps on polar circus are in order

[RuMR]

bikini outlook in Marjorca looks splendid...

[Dru]

maybe some laps on polar circus are in order

 

you, sir, are 30 posts past leet.