Posted 8:03a.m., Monday, April 11, 2011
Tuckerman Ravine has Low avalanche danger today. Natural and human-triggered avalanches are unlikely. WE ARE DONE ISSUING AVALANCHE FORECASTS FOR HUNTINGTON RAVINE FOR THE REMAINDER OF THIS SEASON. You will need to do your own snow stability assessments when using avalanche terrain in Huntington Ravine. A danger of falling ice exists and will persist until it all comes down.
The rain held off through most of the daylight hours yesterday and those who came to play found good conditions and light crowds. Light rain moved in just before sunset and the Observatory recorded a quarter inch of liquid before a lull in the precipitation occurred during the early morning hours. Summit temperatures climbed above freezing for the first time in 5 days and no overnight freeze took place. This combination has set us up for heavy wet snow that has limited potential for slab avalanches but will require attention to sloughing. These point release, loose snow slides will generally be small in nature and won’t cause concern for burial but as heavy as the snow will be they could likely knock you over and take you for a ride. This may be simply annoying in some places but a serious hazard in others such as the tops of cliffs. Keep an eye out for them to occur naturally in the steepest terrain especially if you find yourself out during a heavy blast of rain. We’re carefully watching the potential for rain and meltwater to affect deeper instabilities but at the time we think that the snowpack should be able to withstand the expected rate of percolation.
Rain is forecasted to continue through the day today with 0.5” (1.3cm) to 0.9” (2.3cm) expected over the next 24 hours. The summit should dip back below freezing tonight but I don’t believe that the same will be true for the ravines. Increasing winds today will make even the lightest rain feel pretty miserable and there’s a good chance we’ll feel the boom of thunderstorms as the mercury climbs into the afternoon. As temperatures rise and rain continues to fall things will deteriorate rapidly. Keep a close eye and ear out for icefall as the mountain is getting ready to shed its winter coat. You’ll also want to be very careful if you choose to ski or ride on the riverbed that connects the Bowl to the Sherburne Ski Trail. There’s open water at the very top and undermining will increase today as the flow rates increase.
The Sherburne Ski Trail is still open all the way to Pinkham with good coverage. Soft spring moguls can be found on most of the trail and new hazards will be uncovered as rain and warm temps eat away at the snow.
- 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.
Justin Preisendorfer, Snow Ranger
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2856