There’s plenty of interesting stuff to talk about for the weekend. First off we had a human triggered avalanche in the Lower Snowfields near the top of the Christmas tree. For anyone new to the area, the Christmas tree is a triangular patch of trees to the right of Hillman’s Highway. From the deck at Hermit Lake it looks a lot like a Christmas tree. Chris will be posting a detailed account of how it triggered, size, etc. Look for it in “The Pit” coming later tonight. We’ve also got full on winter conditions here, no corn to harvest this weekend, just plenty of windboard and if you get to the tops of the gullies you’ll find some scoured out ice to try an edge on. Weather wise it’s not ideal, maybe a bit of rain to finish of the weekend.
“Wind speeds sustained at hurricane force, with temperatures plummeting back down to negative numbers.” That’s right off the Mount Washington Observatory morning weather report today, talking about this evening and into Saturday. The optimist’s brief weather window occurs mid-day on Saturday with skies clearing and winds diminishing, but only into the 50’s or 60’s in the valleys, leaving an okay day with temps reaching the high single digits. Not bad if you’re still in winter mode, but it will be pretty brisk if you’re coming up in shorts and a T-shirt. Makes me want to stay in the valley and figure out what I’ll be planting in the garden this spring. Sunday is looking like a mixed bag, lots of potentials. For right now it looks like a possible mix of snow and rain. We’re all obviously rooting for the snow side of things to extend this streak of winter that we’ve got going, but be prepared for another day without spring-like conditions.
Snow conditions are currently OK as far as stability goes. Tuckerman and Huntington both have options for traveling in Low danger today. We suspect this will be the case tomorrow, but with winds cranking up overnight there is a chance we’ll have some locations bumped up a rating tomorrow. As winds decrease tomorrow and any loading slows down, then you’ll be facing the human trigger potential, rather than the natural trigger potential. What we found in the Sluice and Lip today (Friday) could be characterized by saying it’s difficult to trigger, but would be devastating if it were to be triggered. A single skier making smooth turns probably wouldn’t have been enough to create a slide today in the Lip, but getting tripped up in the chop and cartwheeling down might just be enough impact force to initiate an avalanche. Another good way is to put lots of people out on The Sluice and cut turns deeper and deeper into the slab, eventually getting to a point where the slab fails. With so much variability, shallow spots, ice bulges and rocks hidden under 1 inch or 1 foot of snow, there’s always some chance of failure to happen. If we could only run groomers up and down the gullies, that would eliminate some of the variables, but we don’t come to the mountains to ski groomers, do we?
On a side note, with this winter weather and shots of new snow we’ve had more and more opportunities to skin up into the bowl instead of trudging up the hiking trail as we do so often. Skis are ideally suited for traveling in deep soft snow, but you all already know that. As it turns out many people, veterans and first timers alike, for some unknown reason follow a skin track assuming it’s the hiking trail. There is currently a packed trail leading off to the right just at the top of the hill leading up from Hermit Lake. This looks good at the start, but eventually leads into the talus below Lion Head. Most people today unwittingly took this route, and took twice as long to get to the bowl as they would have if they had stayed on the hiking trail. To stay on trail, stay straight as you get near the top of the steep hill. The best lesson we can all gather from this is that you should not blindly follow the tracks laid down by others. They may not have had any idea what they were doing at the time, they may lead to dangerous places, or they might have been made by a Snow Ranger trying to get someplace most people don’t have any desire to go (e.g. to the most unstable snow in the ravine).
To sum it up it’s not spring, it’s gonna be chilly this weekend. Be prepared, enjoy the mountains, and see you soon.
Tuckerman has MODERATE and LOW avalanche danger. The Sluice, the Lip, Center Bowl, Chute and Hillman’s Highway have Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible. Heightened avalanche conditions on specific terrain features exist. Evaluate snow and terrain carefully to identify these concerns. All other forecast areas have Low avalanche danger. Natural and human triggered avalanches are unlikely in Low rated areas.
Huntington Ravine has LOW avalanche danger. All forecast areas have Low avalanche danger. Natural and human triggered avalanches are unlikely.
The latest peak avalanche cycle with new snow and high winds has come and gone. In it’s wake are conditions far from the spring-like conditions many people expect this time of year. We are not yet in a corn snow cycle up here. Cold snow and wintry weather still are the dominate conditions affecting snow stability and other mountain hazards. If you need a reminder that you are in avalanche country check out the crown line from an unintentional skier triggered avalanche in the Lower Snowfields. This hard slab triggered yesterday well after new snow and peak wind loading, could have easily taken a life. The avalanche also fits the Moderate rating so the incident serves as a reminder that safe travel techniques and continual reassessment of stability are key to your long term survival in avalanche terrain. Read more about this incident online in the Pit later today and take an avalanche class.
Our snowpack is currently a mixed bag of travel surfaces as well as stability. Many areas, such as the upper half of Lobster Claw and Right Gully in Tuckerman, and portions of Damnation and Yale in Huntington, are scoured down to an old hard icy surface. Hard slabs and heavily textured sastrugi snow exists elsewhere in the same gullies. Much of the textured snow is still soft enough to break out underfoot and in some steeper sections could be considered an unstable pocket worth avoiding. The most dangerous feature, smooth pillows, was the culprit in yesterdays avalanche in the Lower Snowfields. This snow piled up in lee areas such as the Sluice beneath the ice, low in the Lip, portions of the Center Bowl, and climbers right fork of Hillman’s. These features are best avoided unless you can confidently assess the deeper weakness that allows this slab to fail. Hard slabs are tricky due to the fact that they are not as obvious underfoot like other instabilities in new snow or soft slabs. For this reason we are rating many areas Moderate that are really at the lower end of the rating in terms of the likelihood of a human triggering them. However, if you are the unfortunate winner in the find-the-trigger-sweepstakes you’ll receive a tremendous beating as your prize. It’s the age old risk to reward balance that everyone has to find for themselves.
Safe travel in avalanche terrain requires training and experience. This advisory is just one tool to help you make your own decisions in avalanche terrain. You control your own risk by choosing where, when, and how you travel.
Anticipate a changing avalanche danger when actual weather differs from the higher summits forecast.
For more information contact the Forest Service Snow Rangers, the AMC at the Pinkham Notch Visitor Center, or the caretakers at Hermit Lake Shelters or the Harvard Cabin. Posted 9:00 a.m. April 5, 2013. A new advisory will be issued tomorrow.
Frank Carus, Snow Ranger
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2856