Posted at 8:30a.m., Saturday May 21st, 2011
Tuckerman and Huntington Ravines are under a General Advisory. We have finished using the 5-scale danger rating system for the remainder of the season. You will need to do your own snow stability assessments when using avalanche terrain.
Talk about Deja Vu! Yet another rainy Saturday is upon us, but the developing weather picture is making today look like it could be the worst one of the month so far. A backdoor cold front and instability will trigger thunder and lightning potential later this morning into the afternoon. In their weather outlook the Observatory focused on the possibility of lightning strikes in the alpine zone today which adds to the typical hazards to be concerned about. Once above treeline you will lose control of mitigating this hazard. The higher you are in elevation generally the higher the probability of you and lightning meeting. Due to this I would be quite weary of being above treeline today. As is typical with thunderstorms some heavy bursts of rain can also be expected. No matter where you are anticipate a fair amount of precipitation today so have the appropriate clothing with you. The front should move out tonight and bring improving conditions on Sunday with some sun breaking through the clouds.
Ski runs have changed a lot this week. Hillman’s has fallen apart quite a bit at the bottom and is now requires a bush whack to get into it. The snow in Left Gully has detached from the main bowl near the bottom which also necessitates a short thrash to enter. The Chute has narrowed substantially in the constriction of the hourglass and has a poor runout at the bottom. The lower Sluice has ticked it’s way up the ladder of the best to ski due to the ice above falling which reduces the objective hazards. The lower half from the cliffs down is a reasonable choice, but consider your rock runout below before skiing or riding.
In addition to the weather our traditional spring hazards continue to be an issue. Realize clouds and fog may make identifying them very difficult particularly those that move such as falling ice or people.
- CREVASSES have formed in many areas, the largest of these can be found in the Lip, Sluice, and Center Bowl. Other areas also have smaller crevasses growing. We recommend you hike up the route you plan to descend so you can assess these hazards at a leisurely pace. Crevasse edges are often less stable than they appear, so steer clear of these unless you can safely evaluate their size. Getting yourself up and out of a deep crevasse may be impossible. Imagine what it’s like to be wedged into a constriction wearing skis or a board, barely able to move, and hoping for someone with ropes and anchors to come to your aid.
- UNDERMINED SNOW often hides running water below and it can quickly ruin your day if you break through. Avoid traveling over streambeds and areas of running water and keep a heads up near rocks, bushes, and other areas where the snowpack is thin.
- FALLING ICE has injured and killed many people through the years. We’ve had a lot of ice fall over the past 2 weeks and have made it through the worst of it. However some ice still exists primarily in the Center Headwall. Ice fall doesn’t always go straight down the fall line so it’s not uncommon for Headwall ice to arc into the lower half of Lunch Rocks (or “Icefall Rocks”). Your best defense is to not spend time in areas where ice looms above.
A section of the Tuckerman Ravine Trail is now closed to all use. This section extends from Lunch Rocks to the top of the Headwall where it meets the Alpine Garden Trail, and includes skiing or riding through the Lip area. Only this section of the trail is closed. This annual closure is due to the magnitude of the crevasses and undermining, and the severe consequences of a fall in this area.
The Lion Head Summer Trail is open. This trail has a section that traverses a steep snow slope. We recommend having an ice axe and crampons for safe travel through this section; this is especially important if the trail is frozen and icy. The John Sherburne Ski Trail is closed to all use. Please do not ski on the hiking trail.
- 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.
- A new General Advisory will be issued when conditions warrant.
Christopher Joosen, Snow Ranger
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2856