Avalanche Advisory for Saturday, March 8, 2014

This advisory expires at 12:00 midnight.

Tuckerman Ravine has Moderate and Low avalanche danger today. The Sluice, Lip, Center Bowl, and Chute have Moderate avalanche danger. Natural avalanches are unlikely, human triggered avalanches are possible. All other forecast areas have Low danger. Natural and human triggered avalanches are unlikely except in isolated terrain features.

Huntington Ravine has Moderate and Low avalanche danger today. Central Gully has Moderate avalanche danger. Natural avalanches are unlikely, human triggered avalanches are possible. All other forecast areas have Low danger. Natural and human triggered avalanches are unlikely except in isolated terrain features.

AVALANCHE PROBLEM: From my vantage point as a Snow Ranger, the biggest avalanche problems I expect to see today are the herd mentality and poor safe travel techniques. From a strictly snow stability perspective, the biggest problem is persistent slab with newer wind slab a close second (see below). But, as one who is responsible for assisting accident victims, this time of the year seems to bring out people whose perception of the risks they are taking is vastly different than reality. Don’t be one of these people! Often, to increase your  margin of safety only requires small adjustments that don’t cost you much in time, effort, or enjoyment. When better safety costs so little, there is really no good excuse to not travel in this way. If you have questions about this, seek out one of the Snow Rangers or volunteer ski patrollers working on the mountain today.

WEATHER: It’s been a bit of a dry spell here this past week. On Wednesday we received about 2.7″ (6.5cm) of new snow, which did blow into some areas of the ravines and trigger at least one small avalanche in the Center Bowl. Today we will see increasing cloudiness and some light snow showers in the afternoon. Temperatures will also be falling during the day. Expect travel conditions up high to worsen as the day progresses, so it’s a good day to get an early start and move efficiently.

SNOWPACK: As mentioned above, persistent slabs are the biggest avalanche problem you’ll face today. This is related to the weakened freezing rain crust and another layer of weak snow deeper down. On the whole, the snow above the potential weak layers has a lot of strength. However, it is entirely possible that a slope with numerous sets of boot or ski tracks on it may avalanche. You just can’t know where exactly the weak points are until you find one. 

The most recent snow from earlier this week did load into wind slabs in many areas, but these have had some time to stabilize and have seen some light traffic already. Where you do find relatively soft slab at the top of the snowpack, it is most likely these newer wind slabs. In our field work, we have found these to be on the smaller side and not especially sensitive to human triggering, though the do retain some potential for avalanching. This is true both in areas rated Moderate and in areas rated Low. The difference is is the size and distribution of the wind slab.

Please Remember:

  • 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 Visitor Center, or the caretakers at Hermit Lake Shelters and Harvard Cabin.
  • Posted 8:10a.m. 03-08-2014. 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

2014-03-08 Printable