Weekend Update and Central Gully Incident summary 1-18-2013

Last weekend’s record setting warm temperatures set the stage for hard, icy surfaces in the ravines which are now peppered with potentially unstable windslabs for your weekend adventures. The latest models indicate that the summit will be in the fog with snow showers falling on both Saturday and Sunday while temperatures climb into the mid-teens above zero. On Saturday the wind will be from the west in the hurricane force range (75 mph or 120 kph) before moderating on Sunday into the 40-50 mph (65-80 kph) range. Additionally, the mercury will plunge towards mid-teens below zero Sunday night and into the holiday on Monday. All in all, full winter conditions will be on tap which will test the mettle of even the most experienced mountain traveler over the holiday weekend.

Historically the Snow Rangers see an increased number of incidents and accidents on the MLK weekend. Hopefully this weekend will defy that trend though some signs are already evident.  One is, almost all of the mountaineering gear available for rent in the valley is reserved. This can be a signal that novices have plans to get into steeper terrain where crampons and ice axes are needed.  Our existing snowpack, including trails, have a variable depth of fresher snow over the aforementioned hard, icy snowpack. While good traction exists underfoot with crampons, minor slips can easily turn into long sliding falls when soft snow, which is relatively easy to arrest a fall in, lays over the refrozen, icy snow we have underneath now. Glissading in steeper terrain can also lead to trouble since braking with an axe requires the kind of power only Vince Wilfork can generate.

Another hazard to watch out for are the deep holes camouflaged by the recent snow.  This week brought about 7” of light density snow (10% water) to the mountain, which was blown around by winds through the week from south to northwest. Anyone, like me, unlucky enough to punch through the rotten, warm snow last weekend created a deep hole which is now locked in place. Tread carefully, especially when heading quickly downhill since these little gems have claimed a lot of knees and tib/fib fractures.

Skiers will likely find the steep terrain in the bowls to be a harrowing experience as the surface changes from soft to bullet hard in a matter of a few feet. Unless you plan to shuss the lip with no turns, I would recommend avoiding steeper skiing and head to the lower angled, wind protected woods where the snow has resisted some scouring. Here hard turns which rake off the poorly bonded snow aren’t as necessary as in the steeps.

Thursday night brought dozens of members of volunteer rescue teams to assist snow rangers with an avalanche incident in Huntington Ravine.  Four rope teams of 3 climbers made their way close to the top of Central Gully, a grade 2 snow and ice climb. The upper team triggered a small avalanche (R2 D1.5) which swept 3 of the 4 teams off their feet and down the 45-50 degree slope.  The rope of one of the teams hooked on a rock protruding from the snow, one team was stopped by a really fortunate self-arrest while the third team slid over the ice bulge, fortuitously stopping just before the boulder field.  The forth team, which triggered the avalanche near the top of the gully was the only team to avoid a sliding fall.  The team that took the longest fall was in the center of the gully while the others were along the rock face on the left. No snow anchors were in place and some, if not all, parties where moving simultaneously while roped up, though it isn’t entirely clear how many elected to use this technique.  Rock protection is notoriously difficult to find due to the compact nature of the stone.  This type of multi casualty incident has happened here before, as well as in other ranges in similar terrain, and taxes and potentially depletes available rescue resources.  Fortunately, the injuries this party sustained were relatively minor compared to those who have taken this fall in the past allowing rescue teams to stabilize the situation and evacuate the party via the Forest Service snow tractor. Check the MWAC website for more details and an accident analysis in the near future. Thanks to our volunteer rescuers in helping with this incident!

Friday night January 25th at 6pm, Snow Rangers will talk snow and avalanches during a Friends of the Mount Washington Avalanche Center fundraising event at the Frontside Grind just down the street from International Mountain Equipment in North Conway.  Come on by and join the discussion as rangers will be on hand to share the seasons snowpack history, avalanche safety bullet points, and some of the colorful history of the Mount Washington Avalanche Center.  Friends of Mount Washington Avalanche Center relies on the support and generosity of you so that they can generously support the Avalanche Center.  Come on down and join the conversation!

Take care and safe travels!

Frank Carus,  Snow Ranger

Avalanche Advisory for Friday, January 18, 2013

Tuckerman Ravine has Moderate and Low avalanche danger. Right Gully, the Sluice, Lip, Center Bowl, and Chute have Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible. Evaluate snow and terrain carefully to identify features of concern. Lobster Claw, Left Gully, Hillman’s Highway, Lower Snowfields, and the Little Headwall have Low avalanche danger. Natural and human triggered avalanches are unlikely except in isolated terrain features.

Huntington Ravine has Moderate and Low avalanche danger. Yale, Central, Pinnacle, and Odell Gully have Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible. All other areas have Low avalanche danger. Natural avalanches are unlikely except in isolated terrain features.

In the last two days, Mt. Washington has received just shy of 6” (15cm) of new snow. 3.6” (9cm) of this fell yesterday, which was greater than the forecasted amounts. During this time, W and NW winds were quite strong, gusting into the 80’s and 90’s mph (130-145kph). These did a great job of moving snow around in the ravines and creating stability problems. One very lucky party was avalanched from the top of Central Gully late in the day as they climbed through this newly deposited soft slab. More details will be posted tonight on our Weekend Update section of our website and on our Search and Rescue page.

Bright blue skies this morning are allowing good visibility, though some new blowing snow is obscuring the very top of Central. This shouldn’t amount to much additional loading during the day, so this fact places the emphasis for today on the potential for human triggers. Currently, lots of old, gray snow is visible with fresh white patches of new windslab scattered around. These areas are in the lee of terrain features that often lower the windspeed enough for wind transported snow to be deposited but also in swales and other irregularities in the snowpack. Expect the usual strong degree of spatial variability as you move around today. Examples of the most windloaded locations include in Central Gully above the ice bulge, in pinch points in Odell and Yale, and all the snowfields in Tuckerman across the Lip and Center Bowl. This is not to say other areas are without hazard, so pay attention even in areas rated Low today.

Other areas to consider are the transitions from steep to flat where sluffing snow has accumulated at the base of ice and rock faces as well as at the near the tops of gullies. Given the rounded nature of our geologically elderly terrain, the tops of gullies are often less pronounced than more youthful mountains. So instead of an obvious overhanging cornice, you may encounter gradually steepening snow which has been deposited in the wind rotor created at the “edge” of the ravine. These areas are also features that you should assess very carefully and possibly avoid.

Cold temperatures last night, (-21F, -30C on the summit) have started freezing up the water running through drainage channels. I doubt that the process is complete so be on the lookout for ice dams if you brave the cold today to do an ice climb. The Little Headwall showed an open channel from top to bottom yesterday and snow is now skimmed over what is likely to be a thin veneer of ice. This condition is likely to be encountered on climbs like North, Damnation, Yale, Central ice bulge, Pinnacle…basically all the ice climbs in Huntington plus ice flows in Tuckerman.

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 8:30a.m., Friday, January 18, 2013. A new advisory will be issued tomorrow.

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

2013-1-18 Print friendly