Posted 8:30 a.m. Sunday 4/17/2011
Tuckerman Ravine has Low avalanche danger. Natural and human triggered avalanches are unlikely. Watch for unstable snow on isolated terrain features.
Huntington Ravine is under a General Advisory. 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.
When you close your eyes and think of a perfect spring day in Tuckerman Ravine, today wouldn’t be what you imagined. Snow began last night and transitioned to sleet and freezing rain this morning, with a total accumulation settling down to around 3.5″ (9 cm). It is now raining with some mixed precipitation hanging on. This precipitation is expected to continue through the morning before a cold front barrels through causing temperatures to drop into the teens on the summits. Winds will shift from the SE to the W and increase to 55 to 75 mph (88 to 120 kph) and an upslope flow will develop creating some snow showers in the mountains. Recent and expected weather has us thinking about two variables that you should consider today. The first is snow stability. Today’s upside down snowpack came in on strong SE winds. Field observations this morning showed very little propagation in the new snow and a lot of old surface showing in the Ravine. This has allowed all forecast areas to remain at Low but we like to remind people that Low doesn’t mean no avalanche danger. We think that some isolated areas, particularly the tops of Hillman’s Highway and Left Gully, could have formed some deeper slabs and you may find localized instabilities within the new snow and sleet. The second thing to think about related to weather is how it will change ski conditions. With the invasion of a cold front you can expect the wet surface to freeze up quickly making a nasty breakable crust in the new snow and a solid icy surface in the old snow. If you get out ahead of the cold front you may find some pleasant ski conditions if you’re willing to play in the rain.
A few of our traditional springtime hazards are peaking their ugly heads out of the snow. A few minor crevasses are beginning to show themselves near the Lip and Headwall. Although they could grab a ski or board they are not a real concern yet. The main waterfall hole opened up and is marked by the huge dirt streak near the Headwall and Lip. Do not ski close to this hole and in icy conditions give it some extra room. You absolutely do not want to fall into this hole.
Exiting the Bowl is no longer possible to do without taking off your skis for at least a short distance above the cache. Below the rescue cache the streambed has snow for a short stretch, then you’ll need to head off into the trees, skier’s right, towards the Lower Snowfields to avoid the open water sections of the brook and Little Headwall. Use caution if you choose to descend on skis rather than on the hiking trail. If you have questions, please ask someone who works here, such as a Snow Ranger, Ski Patroller or AMC caretaker.
- 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 Mount Washington Volunteer Ski Patrol, or AMC at the Pinkham Notch Visitor Center or Hermit Lake Shelters.
- This advisory expires at midnight. A new advisory will be issued tomorrow.
Brian Johnston, Snow Ranger