This advisory expires at 12:00 midnight, March 2, 2013
Tuckerman Ravine has CONSIDERABLE and MODERATE avalanche danger today. The Lobster Claw, Right Gully, Sluice, Lip, and Center Bowl have Considerable avalanche danger. Natural avalanches are possible and human triggered avalanches are likely. The Chute, Left Gully, and Hillman’s Highway have Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible. The Lower Snowfields and Little Headwall have Low avalanche danger. Natural and human triggered avalanches are unlikely.
Huntington Ravine has CONSIDERABLE and MODERATE avalanche danger. North Gully, Damnation, Yale, and Central Gully have Considerable avalanche danger. Natural avalanches are possible and human triggered avalanches are likely. Pinnacle, Odell, South, and the Escape Hatch have Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible.
Today conditions are starting the day with ratings that fall in the Moderate range across the board. Based on the existing stability issues, some locations are starting at the upper end of the range this morning while others are falling into the middle or lower end of the Moderate range. During the day, avalanche danger will rise. Some locations will push into Considerable and others will see increasing hazard but still remain within the Moderate rating. We are expecting new snow to fall today, perhaps adding up to a few inches (7.5cm). The new snow will fall with northerly winds diminishing to 15-30mph (25-50kph). This factor will cause avalanche danger to rise as new wind slabs develop. With winds from the north, the slopes facing south will be in the direct lee and will be the first to accumulate new slabs in the avalanche start zones. Relatively light winds such as those forecasted for today tend to put most of the new snow at the upper and middle sections of the gullies, so getting an accurate assessment of stability from below will be challenging.
Yesterday we had some avalanche activity in both ravines. One critical piece of bull’s eye data you can get is recent avalanche activity on similar slopes. This is a clear indicator of the presence of unstable snow. These slabs are currently present in many of the forecast areas, especially those with a southerly aspect. These gullies are the ones that are starting at the upper end of Moderate and will be pushing into Considerable today. Route finding options may be better in the lower-rated forecast areas, but remember that a Moderate rating means we believe it is possible that a person will trigger an avalanche. This may be you, your partner, or someone else dropping in from above you.
I mentioned yesterday’s avalanche activity. Unfortunately, one of those was a fatality in Pinnacle Gully. We know the victim was climbing solo in the gully, but other details are being sorted out at this time. The other avalanche in Tuckerman was a very experienced skier who was carried a short ways downslope when another in his party triggered a slide from above him. There was no burial or injury involved in this incident. We are thankful that this slide ended as it did. Details on both incidents will be posted in the days to come.
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.
Posted 8:30a.m., March 2, 2013. A new advisory will be issued tomorrow.
Jeff Lane, Snow Ranger
USDA Forest Service
White Mountain National Forests
(603) 466-2713 TTY (603) 466-2856