| Posted: 8:39 a.m., Tuesday, January 28, 2003 |
Tuckerman Ravine has CONSIDERABLE avalanche danger. Natural avalanches are POSSIBLE and human triggered avalanches are PROBABLE. Unstable slabs are probable in steep terrain. Be increasingly cautious in steeper terrain.
Huntington Ravine has LOW avalanche danger. Natural avalanches are very unlikely and human triggered avalanches are unlikely except in isolated pockets on steep open slopes and gullies. Normal caution is advised.
The winds yesterday held steady in the 50-75 mph (80-120 kph) range, blowing mostly from the northwest. While these winds scoured out Huntington Ravine quite nicely, they brought a bit of snow down into Tuckerman Ravine. Due to the light density snow moving so easily stability will vary based on exposure to the wind. Strong lee areas probably loaded with deeper new snow while other areas have been blown clean. The arctic air should slow the slab sintering and consolidation process so anticipate unstable slabs to persist through the cold snap. In snow pits dug on Saturday afternoon under the Lip, Right gully, and Right Right gully we continued to find the faceting we have been watching for about the past 2 weeks. We found 1.75 and 2 mm facets between 60 and 120 cms down from the surface between several ice layers. The varing facet depths are due to spatial variablity of different lee loading depths from pocket to pocket. Early facets were found much closer to the surface, but were also quite variable. The tensile strength of the hard slab above these layers are holding the snowpack together beneath the new loading. However, if avalanche activity occurs from continued loading it is possible for it to step down to these facet layers.
Natural ice dam releases occured in Pinnacle gully and Odell's over the weekend in Huntington Ravine. Expect the continued temperature swings to contribute to the dynamics of ice instability. Rock protection is always a better option in these circumstances over ice screws.
THE WINTER LION HEAD ROUTE IS OPEN. The route leaves from the Huntington Fire Road and has orange signs starting on the Tuckerman Ravine trail at roughly the 1.8 mile mark. It is a steep and challenging route. Crampons, an ice axe, and the ability to use them with skill are required for safe travel. Avalanche skills are always required to travel safely in the mountains. Be prepared to do your own stability assessments.
The John Sherburne ski trail is once again improving. Be aware that there are still a few problem waterbars, rocks, and hidden branches from last weeks big wind just under the surface.
AS ALWAYS, THIS ADVISORY IS ONE MORE TOOL TO HELP YOU MAKE YOUR OWN DECISIONS IN AVALANCHE TERRAIN. It should be used along with your own snow stability assessments, knowledge of safe travel techniques, skill in mountain weather's effect on the snowpack, and avalanche rescue.
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