This advisory expires at midnight, March 13, 2012
Tuckerman and Huntington Ravines have Low avalanche danger. Natural and human triggered avalanches are unlikely except in isolated terrain features.
For the last couple days we’ve seen warm temperatures, sunny skies, and loads of skiers and snowboarders out enjoying the weather. The snowpack has been generally stable, with any concerns being limited to surface layer snow catching people in small slabs or sluffs. For the most part, the potential for this problem has been mitigated by skiers, boarders, and climbers cutting up the surface snow. Through this process there were a couple of small slabs released, but nothing major. It was incredibly warm yesterday, starting the day above freezing at Hermit Lake. Around noon yesterday, temperatures at the summit had climbed above freezing and they’ve stayed there since then. This all sets the stage for where your avalanche attention should be focused today.
The slopes today will be subjected to even more warm temperatures, along with some scattered showers or drizzle. There isn’t a lot of moisture in the air, so I don’t think you need to be worried about a heavy soaking rain, but it will be foggy and wet. The snowpack will continue to saturate until temperatures drop back below freezing, which will hopefully happen this evening. I don’t think we’re at a point yet where we need to be thinking about deep wet slab avalanches or a devastating blowout of the waterfall hole, but there is one avalanche scenario to point out. Isolated areas of slab sitting in steeper terrain may be prone to avalanching as they become more saturated. Slopes not yet cut up or tracked out are the most suspect. If this happens, the slide will be small and isolated, but it’ll also be wet and heavy. You’re most likely to see this in out-of-the-way areas such as off in the steep slopes to the left of Left Gully or under the Boott Spur Ridge. In Huntington you may find these kind of issues if you’re trying to descend Escape Hatch or in South Gully. Also think about your sluff management today. Imagine skiing in wet concrete or quicksand on a 45 degree slope and you’ll understand why you should be thinking about this.
We had our first report of spontaneous icefall yesterday, coming from North Gully. That isn’t terribly surprising given the sun and warmth. As much as I hate to admit it, we’re at a point in the season where you should be thinking more about icefall. The Center Bowl has one large column that could do some serious damage if it fell out. Huntington, as you might expect, has a tremendous amount of ice that will eventually all fall down. Today may not be sunny, but the warm rain will continue the melting process.
The Little Headwall has begun its annual deterioration. This winter it never really became a quality exit from the Bowl, so even though it’s still officially winter, it’s time to start thinking about walking out of the Bowl. There are open water holes in the stream above, and in the Little Headwall itself. Snow bridges have only recently developed and will be weakened by the recent weather, and water levels will be up, so be cautious if you choose this route. The Sherburne Ski Trail desperately trying to hold its lower section together. Overall conditions will be soft and slushy with some bare spots.
- 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.
- A new advisory will be issued tomorrow.
Jeff Lane, Snow Ranger
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2856