We are no longer issuing daily avalanche advisories for Tuckerman Ravine this season. However, we will continue to provide snowpack and weather information when conditions change. Avalanches, falling ice and rock, snow undermined by water, large glide cracks, and icy refrozen surfaces all remain potential threats until melt out is complete. We are no longer monitoring conditions in Huntington Ravine, but similar hazards will also persist until snow and ice is gone.
Cool weather will give way to an approaching warm front, though temperatures should remain somewhat cold through the weekend. The summit is forecast to remain below freezing today. Intermittent and partial cloud cover is forecast to continue through tomorrow. Saturday will also bring a chance of rain showers as temperatures warm by a few degrees. Wind today will gust to 90 mph but diminish by afternoon. Warming temperatures on Sunday may allow loose wet sluffing to again become a concern, but until then, the potential for icy refrozen snow makes long sliding falls a primary hazard. Cloud cover and a chance of showers makes Saturday not ideal for skiing. Sunday looks like a sunny day with soft snow. Glide cracks continue to grow and will soon result in closure of the Lip area.
The following hazards have all caused fatalities and should influence your terrain choices:
- Long sliding falls: The melt/freeze cycles of spring can make good corn snow when the snow is not frozen. When frozen, the icy snow is makes travel more difficult and can virtually eliminate your ability to arrest a fall. This refreeze can occur remarkably fast, potentially turning a good ski descent into a conditions better served by crampon and ice axe travel.
- Glide cracks and waterfall holes: As the snowpack gradually gives way to gravity, the slow creep downhill leaves cracks, sometimes called crevasses, in much of our terrain. This is especially prevalent in the Lip, where a large waterfall hole is also present and growing. These cracks and holes will continue to grow. The waterfall area of the Lip has spawned large and destructive wet slab avalanches in the past during periods of heavy rain.
- Icefall: All ice in the ravines will fall down at some point due to warm weather, often in large chunks that travel at high rates of speed. The center and looker’s right portions of Tuckerman Ravine are most exposed to icefall due to the ice in Sluice and Center Bowl. Lunch rocks is a particularly inappropriate place to linger. Consider than speed is safety when passing under any ice flow.
- Undermined snow: In addition to melting on the surface, the snowpack is eroded by meltwater flowing beneath. This creates thin snow bridges that will collapse and are most common over streams and in upper portions of south facing gullies. The sound of running water can sometimes be heard under the snow and is a good indicator of this hazard.
The Sherburne Ski Trail is now closed due to lack of snow. Plan to hike both up and down from Tuckerman Ravine. The Winter Lion Head Route is still open due to the amount of snow remaining on the summer trail.
• Safe travel in avalanche terrain requires training and experience. This bulletin 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, the Mount Washington Volunteer Ski Patrol or the caretakers at Hermit Lake Shelters.
• Posted 8:40 AM, Friday, May 11, 2018. A new bulletin will be issued when conditions warrant.
Ryan Matz, Snow Ranger
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2856