Avalanche Advisory for Wednesday April 2, 2014

This advisory expires at 12:00 midnight.

Tuckerman Ravine has MODERATE and LOW avalanche danger.  The Sluice, Lip, Center Bowl, Chute, Left Gully, and Hillman’s Highway have Moderate avalanche.  Natural avalanches are unlikely and human triggered avalanches are possible.  The Lobster Claw, Right Gully, Lower Snowfields and Little Headwall have Low avalanche danger.  Natural and human triggered avalanches are unlikely except in isolated terrain features.

Huntington has MODERATE and LOW avalanche danger.  Central Gully has Moderate avalanche danger.  Natural avalanches are unlikely and human triggered avalanches are possible.  All other forecast areas have Low avalanche danger.  Natural and human triggered avalanches are unlikely except in isolated terrain features.

AVALANCHE PROBLEM: Persistent Slabs is the main problem today leading us to continue forecasting Moderate avalanche danger for a number of areas.  As was mentioned yesterday areas posted at Low do have good stability but I wouldn’t shut off you mind to nature’s signs leading to avalanche problems.  Excessive heating is the bulls-eye factor leading towards instability so be on the lookout for warming that penetrates into surface slabs weakening them.

WEATHER: Partly sunny skies will prevail this morning before clouding over later today with a chance of snow showers.  Precipitation totals will be scant.  Winds from the W will increase from 30-40mph to 40-55mph later.  Warm temperatures will reign early today, holding above freezing, and then falling through the day and evening before settling in the lower teens.  This morning there are several thermal bands that will likely mix and even out through the day. Avalanche terrain is currently above freezing.

SNOWPACK:  If you’ve been reading our advisories recently you’ll note that persistent slabs have been the issue of late.  This continues to be the main problem to be aware of, but as we move through melt freeze cycles this should abate.  Overnight we went through a brief refreeze, but it did not sustain for long which keeps the persistent concern an issue for me.  When the snowpack stays above freezing around the clock the snowpack loss of strength penetrates more deeply than a consistent 50/50 melt freeze cycle.  The main concerns now are from the Sluice across to the Chute hence their Moderate rating, followed by Left Gully and Hillman’s Highway.

Long overnight refreezing, such as the temperatures we will see tonight, limits the melting and weakening of the snowpack that occurs during the day and locks up surface slabs bridging over weaknesses below. This will likely move us towards some areas at Low tomorrow.  Generally, look for hard freezes at night with minor warm ups during the day initially this early April to let the snow slowly stabilize.

OTHER HAZARDS: Undermined and collapsing snow bridges will likely be the first ‘spring time hazard” to be on the lookout for.  This is mostly an issue for those moving down the brook from the Bowl to the top of the Little Headwall.  Besides avalanche concerns and undermining, the typical objective spring hazards have been held at bay due to the recent late winter conditions.  The Harvard Cabin is closed for the season.

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 or the staff at Hermit Lake Shelters or Pinkham Notch Visitor Center.
  • Posted 8:48 a.m. 04-02-2014. 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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