Avalanche Advisory for Tuckerman and Huntington Ravines

Posted 8:30 Thursday 3-31-2011

Tuckerman Ravine has Moderate and Low avalanche danger.  The Lobster Claw, Sluice, Lip, Center Bowl, the Chute and the Lower Snowfields have Moderate avalanche danger.  Natural avalanches are unlikely and human-triggered avalanches are possible.  Right Gully, Left Gully, Hillman’s Highway, and the Little Headwall have Low avalanche danger. Natural and human-triggered avalanches are unlikely in these areas.  Watch for unstable snow on isolated terrain features.

Huntington Ravine has Low avalanche danger. Natural and human-triggered avalanches are unlikely.  Watch for unstable snow on isolated terrain features.

Even though the sun finally popped out yesterday, winds kept slopes cool allowing some instabilities from last weekend’s storm to linger.  This event gave us about a foot of low density snow which has been transported since on NW winds.  Loading diminished to become insignificant on Wednesday as we enter a brief lull until tomorrow’s weather maker. The main areas of concern continue to be the Lip and the Center Bowl followed by their outliers, namely the Sluice and the Chute. The Lobster Claw has stable snow along the climber’s far right side which is also where most of the gully’s traffic has been.  The upper reaches of the climber’s right fork and the entire left fork from the bottom of the “Y” have more snow of concern and is the cause for the Moderate rating.  Brian and I were impressed with the amount of snow the Lower Snowfields picked up during the prolonged loading event following the weekend storm.  It is on the lower end of the Moderate rating, but not quite down to Low.  You will find a lot of spatial variability in this diverse forecast area that stretches from Hillman’s Highway to the Little Headwall.  Hillman’s Highway has pockets of snow to be aware of particularly in some isolated locations in the climber’s right hand fork.  In Right gully the climber’s left wall, which has an easterly aspect, have some isolated terrain features to watch.

The big news is the impending Winter Storm bearing down on the Northeast.  The National Weather Service (NWS) has issued a Winter Storm Warning from 2 am Friday morning until 8pm.  This Nor’easter has good agreement between models so we are confident we are in for a wallop. Initially snow will be lighter density with low wind speeds from the East.  Wind speeds will ramp up a bit before the shift towards the N occurs, likely moving snow from the earlier thin blanket.  I would expect cross-loading on W and SW slopes to occur during this period.  As daylight appears tomorrow snowfall intensity will increase, snow density will get heavier, and winds will increase to 60+mph (97kph) as they begin to shift and come from the NNW.   Total snowfall may surpass 12” (30cm) at higher elevations.  The NWS is forecasting 8-15” (20-38cm) for the region.  You will likely see a number of “High” ratings tomorrow with the potential for a Considerable or two, or even…… yes the “E” word…..Extreme.  If the system continues to pan out as expected travel in avalanche terrain will not be recommended tomorrow.  I would also expect lingering avalanche issues into the weekend with some elevated danger ratings.

The Lion Head Winter Route is filling in and evidence of recent avalanche activity can be found on both sides of the route.  The best line up the ridge is marked with bamboo poles.  Stay on this path to avoid the more significant avalanche terrain on either side. Saturday night April 2nd will be the last night the Harvard Cabin will be open this season.  After that, the only place you can camp on the east side of Mt. Washington will be at Hermit Lake Shelters in Tuckerman Ravine.

Please Remember:

  • 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

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