General Bulletin for Monday, January 11, 2016

 

A new General Bulletin will be issued if conditions warrant or within 72 hours of this release. General Bulletins are issued when isolated areas of unstable snow may exist within the forecast areas. Forecasts using the 5-scale danger rating system will begin when snowfields and bed surfaces become more developed. Please remember that avalanche activity may occur before the issuance of a 5-scale danger rating forecast. As always, make your own snow stability assessments when traveling in avalanche terrain.

The ravines took a hit yesterday from the precipitation that fell around the region. The summit reported 1.4 inches of liquid on Sunday.  What little snow was in the ravines was completely saturated and is now well on its way to becoming a skating rink.  Temperatures plummeted since yesterday, with the summit dropping toward 0 degrees Fahrenheit as of Monday morning.  Expect all snow fields to be harder than concrete and rocks to be glazed with a layer of ice.  The largest snow fields are in Left Gully, the Chute, and Central Gully in Huntington.  Long sliding falls are a distinct possibility in any of these places, including the snowfield below the first pitch of Pinnacle.  Despite relatively small snowfields, it will be easy for any object to reach terminal velocity quickly and then ricochet through all the uncovered rocks abounding the ravines. Ice climbers can expect to find ice dams, and hollow and undermined ice in places with running water creating lots of potential for frozen ropes until the arctic lockup settles in.

The weather for the upcoming days looks to be a true dose of Mount Washington winter. Upslope snow showers will bring up to a few inches to the summits today.  This snow, combined with steady hurricane force winds and temperatures dropping below zero will make mountain travel difficult.  Winter weather will likely continue through Wednesday, with the possibility for several inches of snow Tuesday afternoon into Wednesday morning.  With the icy surface left that developed due to Sunday’s rain and the wind loading that will occur over the next 72 hours, expect snow fields to grow and develop potentially reactive wind slabs. Higher wind velocities such as those that are forecast tend to build wind slabs lower in our terrain….precisely where the largest of our small snowfields currently reside. Even small avalanches can have grim consequences given the icy bed surface and rocks. Remember: if a snowfield is large enough to recreate on, it’s large enough to avalanche.

  • Safe travel in avalanche terrain requires training and experience. This bulletin 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. Bulletin posted at 7:25am January 11, 2016.

 

Helon Hoffer/ Frank Carus, Snow Rangers
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2856

2016-01-11 GENERAL2