Posted 8:15a.m., Monday, February 14, 2011
Tuckerman Ravine: the Sluice, Lip, Center Bowl, and Hillman’s Highway have Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible. The Lobster Claw, Right Gully, the Chute, Left Gully, the Lower Snowfields, and the Little Headwall have Low avalanche danger. Natural and human triggered avalanches are unlikely.
Huntington Ravine: Central Gully has Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible. All other forecast areas of Huntington have Low avalanche danger. Natural and human triggered avalanches are unlikely. Watch for unstable snow on isolated terrain features.
For all you snow lovers out there, this Valentine’s Day isn’t going to be the kind of day you fantasize about, but avalanche conditions are interesting enough that you might want to peel off a couple layers and admire the snowpack. Just don’t bring flowers; that would be a little weird. Like yesterday, there are a couple of concerns for you to watch for. First are the existing instabilities, some of these are older and becoming less of a concern over time and some of these are more recent. Yesterday, 1.7″ (4.3cm) of snow fell on the summit while winds blew generally from the W at 50-70mph. This new snow is the cause of Central Gully being bumped up one rating from where it was yesterday. In other areas of Huntington you might want to watch for any isolated instabilities, particularly in sheltered lee areas. Around Tuckerman you’ll find slabs of varying ages and hardnesses. Some of the oldest ones that still hold avalanche potential are in the Sluice, Lip, and Center Bowl. On top of the older, harder slabs is some newer snow that’s blown in, but for the most part this takes a back seat to the aforementioned slabs in these areas. In other areas, such as Hillman’s, you’ll find sections with relatively softer slabs. Field tests yesterday had these failing within the slab itself, rather than at an interface between two distinct layers. Good stability can be found in some areas of Tuckerman by searching out the snow that got pounded into submission by strong winds. You’ll find this in much of the Lobster Claw, Right Gully, and Left Gully.
The second concern today is related to the incoming weather. Today will be a warm day for sure. It’s already above freezing here at Hermit Lake and summit temperatures are forecasted to reach into the lower 20’s Fahrenheit. New snow is forecasted for the afternoon and evening hours as well. I’m hopefully that temperatures will stay low enough at our elevation that any new precipitation falls as snow. By the end of the day we might see an inch or maybe two, which, when blown in on strong W winds (50-70mph/80-113kph) will have the ability to create new slabs or build on existing ones. Watch what the weather is doing today. Look for indicators such as snow starting earlier or heavier than expected, or if those droplets hitting your face are actually rain and not snow, these should tell you that avalanche danger may soon be on the rise.
- 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.
Jeff Lane, Snow Ranger
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2856