| Posted: 8:28 a.m., Sunday, January 26, 2003 |
Tuckerman Ravine has LOW AND MODERATE avalanche danger today. The Little Headwall and the Lower Snowfields have Low avalanche danger. Natural avalanches are very unlikely and human triggered avalanches are unlikely except in isolated pockets. Normal caution is advised. All other areas in Tuckerman have Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are POSSIBLE. Unstable slabs are possible in steep terrain. Use caution in steeper terrain.
Huntington Ravine has LOW AND MODERATE avalanche danger today. Yale, Damnation, and North gullies have Low avalanche danger. Natural avalanches are very unlikely and human triggered avalanches are unlikely except in isolated pockets. Normal caution is advised. All other areas in Huntington have Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are POSSIBLE. Unstable slabs are possible in steep terrain. Use caution in steeper terrain.
The summit received .7 inches of new snow in the past 24 hours with precipatation forecasted to continue through the day. The valleys are expected to pick up 1-2 inches of snow with the mountains anticipated to receive 1-3 inches. Winds are currently around 60 mph and are forecasted to move to the SW later and diminish slightly. Light snow is currently falling and all weather data is pointing to the forecast playing out. 1 to 3 inches with 40-50 mph westerly winds is a classic scenario to pick up enough unstable slabs in lee eastern pockets to create a real avalanche problem. I say this because these lower snow amounts don't register in peoples minds as setting up unstable slabs causing possible avalanches. "Currently", the avalanche danger is Low, but with snow coming in through the day we expect most slopes and gullies in the Ravines to be Moderate later today, hence the "Moderate" forecast. The northern gullies in Huntington were left at Low, but expect some cross loading to occur. If we get more than the forecasted snow, which appears unlikely, expect the avalanche danger to potentially increase beyond the current advisory. You may see Moderate moving to Considerable and Low moving to Moderate. Snow is forecasted to continue through the night so expected an elevated rating for tomorrow. So, "currently" you will find most areas scoured down to old surface and hard wind slab. In a few strong lee areas you may find pockets of slab that are unstable such as under the Lip and the northern side of Tuckerman. As you move south toward the Chute and Left Gully, you will find a harder wind slab and old surface. In snow pits 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 from pocket to pocket. The tensile strength of the hard slab above these layers are holding the snowpack together. However once new snow avalanche activity occurs over this layer or a weather event such as rain or a thaw melts hard slab bonds these facet layers may facilitate slope failure. We will keep an eye on this developing problem.
Natural ice dam releases occured in Pinnacle gully and O'Dell's yesterday in Huntington Ravine. Expect the continued temperature swings to contribute to the dynamics of a changing ice mass. 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 quite messy right now due to midweek high winds of 145 mph. We have been working on getting larger branches and debris off the trail, but it would take 3 dozen people a week to manicure it so expect lots of sticks cones and needles. Skins would be a better option than a wax choice due to the 2 inches of crude you'd probably get on your bases. Be aware that there are still a few problem waterbars and rocks hidden 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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