Avalanche Advisory for Friday, April 6, 2018

Huntington and Tuckerman Ravine have LOW avalanche danger today. All forecast areas have Low avalanche danger. Generally safe avalanche conditions exist. The Little Headwall is no longer forecast due to a lack of snow. Certain areas may exceed this rating later in the day if we see the upper end of forecast snow totals.

AVALANCHE PROBLEM: Until snowfall begins later in the day, the avalanche problem is nonexistent. The greater hazard is long, sliding falls due to the firm nature of the snowpack. Up to 3” of snow may appear by tonight on eventually increasing SW wind. This has the potential to create sensitive wind slab, whose size will largely depend on the amount of snow we receive. If we see the higher end of forecast snow totals (4” by midnight) we potentially could exceed the Low rating in certain forecast areas. Southwest wind will load slopes on the looker’s left side of both Ravines as well as potentially cross-load the Headwall area of Tuckerman and the Central Gully in Huntington. For those recreating later in the day, keeping an eye on how much snow falls and how the wind effects this will be crucial to safe travel.

WEATHER: Yesterday saw bountiful blue skies over the White Mountains with cold temperatures and strong wind. Today, wind will decrease from the triple digits of yesterday with warming temperatures and afternoon snowfall. Low pressure is bringing a weak warm front from the west that will allow clouds to develop along with summits fog. The following cold front will create snowfall in the afternoon and evening, possibly exceeding 4” by tomorrow morning. Temperatures today should reach into the upper teens F on the summit by evening. Current wind from the west at 50mph should decrease midday to the 25-40mph range while shifting to the SW and then back up to 60mph as darkness encroaches.

SNOWPACK: Our current snowpack is largely defined by the two melt-freeze cycles that occurred over the past week, one last Friday and again on Wednesday.  Below this crust, dry, finger to pencil hard snow exists, but will be hard to access due to the knife-hard melt-freeze crust. A few rounds of a trace to an inch of snow fell on very strong winds in between these two melt-freeze cycles, but the strength of the wind was enough to push the majority of this snow out of avalanche terrain. A few pockets of wind slab likely formed under rock buttresses, but for the large part, today’s snow will fall on the melt-freeze crust. The combination of sunshine, warming temperatures and decreasing wind may allow for some softening of south-facing slopes. New snow may have a harder time adhering to slopes that remain firm, something to keep tucked away in the back of your mind of making travel decisions later in the day.

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.
• Posted  6:45 a.m., Friday, April 6, 2018. A new advisory will be issued tomorrow.

Helon Hoffer, Snow Ranger
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2858

2018-04-06