Avalanche Advisory for Sunday, December 14, 2014

This advisory expires tonight at 12:00 midnight.

Tuckerman Ravine has MODERATE and LOW avalanche danger. The Sluice, Lip, Center Bowl, the Chute, and Left Gully have Moderate avalanche danger. Natural avalanches are unlikely and human-triggered avalanches are possible. Lobster Claw, Right Gully and Hillman’s Highway have Low avalanche danger. Natural and human-triggered avalanches are unlikely. Lower Snowfields and the Little Headwall are not posted due to lack of snow cover. Watch for unstable snow in isolated terrain features.

Huntington Ravine has MODERATE and LOW avalanche danger. North, Damnation, Yale, Central, Pinnacle, and Odell have Moderate avalanche danger. Natural avalanches are unlikely and human-triggered avalanches are possible. South and Escape Hatch have Low avalanche danger. Natural and human-triggered avalanches are unlikely. Watch for unstable snow in isolated terrain features.

AVALANCHE PROBLEM: Wind slab is the primary avalanche problem for today due to recent snow being redistributed around the mountain by strong N and NNW winds yesterday. These slabs formed on a variety of potential bed surfaces, including water ice and ice crusts from the recent thaw as well as lighter density storm snow. Expect to find these slabs in lee areas and gullies which generally face south and east. They may be on the smaller side due to our early season snowpack, but they could pack a punch especially if the sweep you down rocky terrain. Slabs formed from sluffing and spindrifting snow (a.k.a. Loose-Dry avalanches) run a close second on the list of avalanche concerns. Expect these firm slabs beneath steep terrain features and approaches to steep pitches of ice.

WEATHER: Yesterday around 2.5″ (6 cm) of new snow were recorded on the summit though only a trace (.5 cm) was collected at Hermit Lake. Regardless of the total amount of new snow, strong wind transport occurred for a 4 to 5 hour period mid-day yesterday when winds were steady in the 50-60 mph (80-95 kph) range with gusts to 70 mph.

Relatively warm temperatures today will continue to improve snow stability. Today’s weather forecast marks a break from our unsettled weather due to the Low pressure which has been parked off the coast for the past week. Though temperatures will warm into the 30’s F at mid-elevations today, expect lingering clouds, flat light and some fog to hamper visibility at times. Wind from the NW will diminish to the 20-35 mph range, though gusts to 55 mph will remind you why you carry goggles and spare gloves here. The temperature on the summit at 8 am was a balmy 19F and will approach the freezing mark through the day. Enjoy the warmth while it lasts since the coldest month of the year is right around the corner.

SNOWPACK: Somewhere in the neighborhood of 2′ (60cm) of snow exists in wind sheltered areas of higher terrain. With the exception of the new snow (3-7″, depending on location) that has fallen in the past 48 hours, most of this snow is encapsulated by a stiff crust of refrozen snow. Beneath this crust another ice lens existed. Relatively warm temperatures have helped to further stabilize these deeper layers leaving us with wind slab and sluff slab as our main concern.

The summer Lion Head trail to the summit remains open and is the safer option than other choices on the east side of the mountain. A variety of hiking conditions exist, with traction devices, including crampons and ice axes, recommended, if not required for travel near and above treeline.

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.
  • Posted 8:30 a.m. December 14, 2014. A new advisory will be issued tomorrow.

Frank Carus, Snow Ranger
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2856

2014-12-14 print friendly