Avalanche Advisory for Wednesday 1-23-2013

Expires at Midnight 1-23-2013

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

Huntington Ravine has Moderate and Low avalanche danger. Central, Pinnacle, Odell, and South gullies 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.

I can’t speak for you, but if I caught myself recreating above treeline today I think I’d borrow Joe’s straight jacket and commit myself.  It’s cold!  Although in principle we still have another 236 degrees C to go before getting to absolute zero on the Kelvin scale where particles theoretically stop, it’s frigid enough for me.  The summit is currently at -35F with winds gusting to 75-80mph.  I usually don’t like getting into windchill, but at around -90F that’s worth noting.  At Hermit Lake it’s about -19F which made doing the snowplot measurements for Joe a little rugged.  This weather is keeping most away from the mountain as it feels like a ghost town up here with just a few people scattered about.  Since I didn’t see you this morning you’re obviously pretty smart to wait for a more reasonable day.  It’s the kind of day where one minor issue can spiral into disaster, a.k.a.- “no mercy conditions”.

The mountain picked up just under an inch of snow yesterday and may get up to that much today.  I have a snow geek challenge today.  It’s a little cold for much snow to fall so if you are out and about anywhere and you see frozen particles floating down make a note of the crystal type and the associated air temperature and let us know what you saw.  We encountered a surprising amount of drifting on the trails this morning so I would expect we picked up a little bit more loading in some of our avalanche terrain overnight, albeit light.  Avalanche conditions shouldn’t change too much over the next couple of days. The cold air that moved in yesterday with the high pressure system will keep us very cold into the weekend. These temperatures slow snow sintering and stabilizing of weak slabs.  So expect the current instabilities that we have scattered in the two ravines to linger with little consolidation.

The focused instability concerns in Huntington Ravine can be found near the top and in the midsection choke points of South, Odell, Pinnacle and Central and to a lesser extent in mid-section chokepoints of Yale and Damnation.  Look for larger areas of unstable slabs to be found in Tuckerman’s Chute, Center Bowl, Lip and Sluice. I would consider these four Tuckerman forecast areas to be on the upper end of the Moderate rating definition, just coming down from yesterday’s Considerable.  Remember that although we use 5 different ratings to explain the avalanche likelihood and consequences snow doesn’t act in 5 specific ways so think of instability as a continuum on the spectrum between “Low” and “Extreme”.

In addition to extreme cold and avalanches think about the old hard surfaces that are still causing a traction problem in a number of locales. These old surfaces are camouflaged by newer snow in places and threaten skiers and climbers with long sliding falls.  Windblown snow is also hiding undermined areas of snow and ice from the recent thaw as well as newly formed ice so crampons will likely be needed sooner and on lower angled terrain than you might think.

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 8:28a.m. 1-23-2013 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

Print Version 1-23-2013