Posted at 6:30, Wednesday, February 23, 2011
Tuckerman Ravine has MODERATE and LOW avalanche danger. The Center Bowl, Lip, Sluice and Right Gully have Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible. Hillman’s Highway, Left Gully, the Chute, Lobster Claw, Lower Snowfields and the Little Headwall have Low avalanche danger. Natural and human triggered avalanches are unlikely. Isolated terrain features may hold pockets of instability in these areas.
Huntington Ravine has LOW avalanche danger. Natural and human triggered avalanches are unlikely except in isolated terrain features.
If you are reading this as you pack the last of your goodies into your pack for today’s mountain adventure, LUCKY YOU! You are going to be treated to a beautiful winter day with summit temperatures in the mid-teens F, decreasing winds and clear skies. There are a lot of options for climbers with generally stable snow conditions in Huntington and a variety of snow gullies in Tuckerman that fall within the Low avalanche danger rating. Last week we had a warm up and one dominate surface you will notice is a crusty layer that formed when temperatures fell back below freezing last Saturday. This drop in temperatures was also accompanied by a half a foot of snow and strong winds which accounts for the other surface layers you will find today. Strong winds blew snow into the Ravines on Saturday resulting in a natural avalanche cycle. Since then we have had less than 1″ (2.54 cm) of new snow but persistent winds continued to find snow to transport into Tuckerman Ravine. These recent events are the cause of existing snow stability concerns. In areas posted at Low, such as the Chute, Lobster Claw and Lower Snowfields, you will find deposits of wind transported snow mixed in with the crusty surface. Be aware that isolated areas of instability may still exist in forecast areas posted at Low. The areas posted at Moderate have larger deposits of wind slab with the Lip and Sluice being the primary concerns today. Their smooth creamy looking surface is tempting but I think they have the best potential for avalanche activity today. The late February sunshine will remind us that spring is not too far away. I think today’s weather will help existing slabs move toward stability in the long run.
Tomorrow’s weather won’t be quite a repeat of today’s but it is looking pretty nice. Expect tomorrow’s stability issues to be similar to today’s with some added benefit of time and heat on south aspects. Snow is in the forecast for Friday with light accumulation expected. We will keep you posted on this event and how it may impact your weekend plans in the coming advisories.
- 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.
Brian Johnston, Snow Ranger
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2856