Posted 8:30, Saturday, January 8th, 2011
Tuckerman Ravine has LOW and MODERATE avalanche danger. The Lobster Claw, Right Gully, Left Gully, and Hillman’s Highway have Low avalanche danger. Natural and human triggered avalanches are unlikely. Watch for unstable snow in isolated terrain features. The Sluice, Lip, Center Bowl, and the Chute have Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible. The Lower Snowfields and Little Headwall remain not posted due to a lack of snow in these areas.
Huntington Ravine has LOW avalanche danger. Natural and human triggered avalanches are unlikely. Watch for unstable snow on isolated terrain features. The Escape Hatch remains not posted due to a lack of snow in this area.
Over the past 48 hours snow stability has been slow to change, but some slight movement towards stronger snow has been occurring in areas that have been posted at Moderate in Tuckerman Ravine. Mean while all areas in Huntington have been posted at Low over the past 2 days due to the scouring high winds that blew early in the week. Little has changed in these areas with only about a half an inch (1.25cm) falling since the icy surfaces were exposed by 2-3 days of hurricane force wind velocities. Expect continued hard surfaces in the vast majority of Huntington offering good cramponing for ascending. Conversely, these surfaces will offer rapid decent of a dropped glove or you if you get tripped up. Putting crampons on early and good self arrest skills are both crucial for a safe climb in Huntington or a summit trip if on steep snow.
The main stability problems continue to remain in the Lip and Sluice of Tuckerman due to them being in the direct lee of NW windloading that occurred several days ago. The Center Bowl over to the Chute has been more wind affected offering a slight increase in stability comparatively, but still fall within the Moderate rating. Right Gully and the Lobster Claw have dropped to Low due to some solar gain which increased slab temperatures just a bit more than easterly aspects, and some compaction from people. Right gully has seen the most visitor use of all areas over the past 24 hours, albeit limited. Some ski traffic occurred in the lower third of the gully which initiated a very small slab avalanche just below the narrows in the mouth of the gully. This was quite small and innocuous, but does give us a little data about stability and the amount of variability that can be found out there right now. Anticipate finding a high degree of spatial variability in areas posted at both Low and Moderate. In areas posted at Low you will find hard old surfaces with some newer slabs that qualify as “isolated pockets”, particularly in those areas posted at Low in Tuckerman Ravine. In areas posted at Moderate you may find stability one minute and weaker slabs the next, especially as you move into higher strong lee areas of the Sluice, Lip and their immediate outliers.
If the weather forecast become reality over the next 24-48 hours some upslope snow will be associated with a drop in temperatures, a counter clockwise shifting wind direction from the SE to the NW, and increasing velocities from very light to 80+mph (145kph). The vast majority of these changes that will affect snow stability will occur tonight and tomorrow. I would put money on the temperature and wind forecast, but will wait and see what happens for precipitation as upslope snow can be a bit hit or miss. Expect anywhere from a trace to 5” (12.5cm) over the next 36 hours. So… stay tuned for our advisory Sunday and Monday morning for updates on how this develops.
The Tucks trail continues to ebb and flow between icy hell and not so bad. Right now it’s nowhere near as bad as it’s been, but the majority of users have been wearing crampons or other traction devices with ski poles. Much of the ice is covered by a dusting of snow so be thoughtful about foot placements particularly on the way down. A few new ice flows have been slowly growing which may change the conditions again this week. The Sherburne ski trail is rugged, poor, bad, bare, icy, turf riddled, etc. Enough said for most users but to spell it a little more clearly we need more snow to make a decent of this trail at all worth it.
- 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.
- This advisory expires at midnight. A new advisory will be issued tomorrow.
Christopher Joosen, Snow Ranger
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2856