Posted 7:30 a.m., Friday February 4th 2011
Tuckerman Ravine has CONSIDERABLE avalanche danger. Natural avalanches are possible and human triggered avalanches are likely. The only exception to this rating is the Lower Snowfields which has Moderate avalanche danger and the Little Headwall which is Low.
Huntington Ravine has CONSIDERABLE and MODERATE avalanche danger. Central, Pinnacle and Odell have Considerable avalanche danger. Natural avalanches are possible and human triggered avalanches are likely. All other forecast areas have Moderate avalanche danger. Natural avalanche are unlikely and human triggered avalanches are possible.
Early this morning the summit begin recording the highest wind speeds of the month so far. February being only 4 days old, the greater point is they are the greatest velocities since the beginning of the last storm which brought between 11 and 15” (28-38cm) to the mountain. In addition the flow is moving in from the W which is most influential for loading widespread slab in the Ravines. Therefore as alluded to in Thursday’s advisory today’s loading will increase the concern for natural and human triggered avalanches in most areas due to forecasted wind speeds maxing out at 70+mph (112+kph). Gusts of 67 and 69 mph were observed between 2 and 3am this morning creating some loading but speeds subsided at daybreak limiting snow movement. If we stay in the 50mph range we will struggle to meet the Considerable forecast in some areas today. But the predicted snow showers coupled with higher winds the Considerable rating will come to fruition. As the day wears on a number of S and N facing slopes like Right gully in Tuckerman and South Gully in Huntington will become cross loaded, but the slopes in the direct lee of W winds will accumulate the most new snow deposition. The Lip across the Center Bowl to the Chute in Tuckerman Ravine will have the greatest potential for natural activity as winds increase today. For ice climbers heading into neighboring Huntington Odell through Central will be in the bull’s-eye for W wind deposited slabs. New loading will also fall on a variety of slabs that were created during the later portion of the storm which may push some of this cold snow beyond what it can handle for load.
So outside of a brief forecasted snow shower it’s starting out as another bluebird day. However the expected active loading will require vigilance on your part to watch conditions and give the snowpack a true honest assessment. Like most individuals when you want to do something (play in the mountains) you’ll be looking for the answer you want so you can do it. Be objective, the snow is. What I mean is the snow isn’t thinking “come on hurry up I can’t hold on much longer I’m ready to explode!” It’s thinking,… well nothing. When the physical properties of stress versus strength are surpassed… voila… fracture and failure= avalanche. Snow stability is not with you or against you it just is so study it and it will provide most of the answers. When you can’t get all the answers be conservative.
Although tomorrow’s snow event has fizzled out to about a 2” (5cm) projection the snow cycles just keep on piling up which makes me smile. We’ll get into Tuesday’s and Thursday’s snow events in a couple of days, but we are certainly getting into a favorable rhythm to keep the winter mountains freshened up. Check back early this evening for the Friday Weekend Update on www.mountwashingtonavalanchecenter.org for updates on today’s loading and tomorrow’s new snow.
- 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.
Christopher Joosen, Snow Ranger
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2856