Date: Lundi, 18 Février 2002
Temps: 8h19
TUCKERMAN AND HUNTINGTON RAVINES HAVE LOW AVALANCHE
DANGER. Natural avalanches are very unlikely and
human triggered avalanches are unlikely except in
isolated pockets on steep snow covered open slopes
and gullies. There is generally stable snow, but
these pockets do exist so pay attention as you move
through avalanche terrain. Normal caution is advised.
Once again our hopes for new snow have been dashed.
We only received a trace of new snow yesterday.
A chance of snow is in the forecast for Thursday.
The North or right side of Tuckerman Ravine has
more instability than the southern side though still
staying within the Low rating. Because of the strong
lee nature and our prevailing winds, areas under
the Lip, Sluice, and Right gully may have pockets
of softer hard slab than the southern side of the
ravine. In addition, unconsolidated snow can be
found under a thin slab and surface crust in some
southern facing pockets. Although the tensile strength
of the crust is still holding the slab together
the shear strength of the unconsolidated facets
is weak. I think it would take a considerable force
to release these pockets, but an aggressive skier
or rider may find the right sweet spot to trigger
this weakness. Areas under the Sluice and left of
center have wind pack dominating the snowpack. Also
be aware that an ice crust is interspersed through
some areas of the bowl and with flat lighting this
may be hard to ascertain.
With the warm weather last week followed by cold
temperatures you should anticipate ice dams. Water
running from ice tool placements have been reported
in numerous locations so be cautious for hydrolic
pressure in commonly found areas such as over the
top of bulges and steep columns.
THE LION'S HEAD WINTER ROUTE IS OPEN. Follow the
orange Lion Head signs off of the Tuckerman Ravine
trail about 1.75 miles up from Pinkham. This is
a difficult steep route so crampons, ice axe, and
mountaineering skills are essential.
Coverage on the John Sherburne ski trail is fairly
good, but we did loose some snow with yesterday's
warm weather. Expect conditions to be a bit firm
as the entire trail went above freezing on Saturday.
PLEASE REMEMBER:
Any new precipitation may increase the avalanche
danger, this includes wind transported snow.
Obtain latest weather forecast before starting out.
For more information, contact the U.S. Forest Service
Snow Rangers: AMC at Pinkham Notch Visitor Center
or Hermit Lake Shelters.
This bulletin expires today at midnight and the
next avalanche bulletin will be issued tomorrow.
Marianne Leberman, Snow Ranger
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2856