Avalanche Advisory for Saturday 2-18-2012

Expires 12:00 midnight, February 18, 2012

Tuckerman Ravine has CONSIDERABLE and MODERATE avalanche danger.  The Sluice, Lip, Center Bowl, and Chute have Considerable avalanche danger. Natural avalanches are possible and human triggered avalanches are likely. Right Gully, Lobster Claw, Left Gully, and Hillman’s Highway have Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible. The Lower Snowfields and the Little Headwall are not posted due to an overall lack of snow. Forecasts for these locations will begin when conditions warrant.

Huntington Ravine has CONSIDERABLE and MODERATE avalanche danger.  Yale, Central, Pinnacle, Odell, and South gullies have Considerable avalanche danger. Natural avalanches are possible and human triggered avalanches are likely. North, Damnation, and the Escape Hatch have Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible.

If you’ve been spending your time down in the valleys over the past two days, you might be wondering why avalanche danger is where it is. After an uncomfortably cold morning in Tuckerman yesterday, I was shocked to drive down into sunny 40F temperatures in Gorham. The past couple of days have been very winter-like up here, and we’ve even received a couple shots of new snow. So far, the snow totals have been 3” at the summit, with another 1-2” forecasted for today. We estimate that roughly the same amount has fallen at lower elevations, but the winds have conspired to prevent us from accurately measuring this snowfall. This has all taken place since early Friday morning, and during this time winds have slowly ramped up from SW 15mph (24kph) to the current WNW 50-60mph range (80-97kph). Today we’ll have a little more snow this morning, followed by a brief break in the weather, and then another snow shower in the afternoon.

With the winds acting as they have been, we have concerns about the potential for both naturally triggered and human triggered avalanches. Both of these concerns are made worse today by the fact that it’s a Saturday on a holiday weekend, and visibility is incredibly poor. Don’t make the mistake of unknowingly being in an avalanche runout path, because you won’t have any indication of what’s going on above you. The areas that are most concerning are in the middle of both Tuckerman and Huntington Ravines. Going to the floor of Tuckerman to “take a look” or hiking around on the fan in Huntington will put you at risk of avalanches from above.

The snowpack prior to the new snow was generally stable in all aspects. South-facing slopes received strong solar gain on Thursday, causing the top layers to moisten and subsequently refreeze. East-facing and north-facing slopes didn’t get this new crust development, but there were some places with an older crust exposed at the surface. The northern gullies in Huntington and Lobster Claw and Right Gully will have the best travel options for avoiding newly deposited slabs, but you should expect any new slabs that did develop to be unstable as they are likely sitting on top of a slick crust.

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 Pinkham Notch Visitor Center, or the caretakers at Hermit Lake Shelters or the Harvard Cabin.  
  • Posted 8:35am. 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

2012-02-18 Print Friendly