Tuckerman Ravine photos, Dec. 23, 2016

The Lip with Open Book standing tall again. It grew again after last week’s rain. Lunch Rocks is in the foreground with Sluice on the upper right.

Pockets of wind slab beneath the ice and on the TRT where it traverses the Lip but icy crust dominates.

Duchess, Hillman’s and Dodges Drop are filling in.

Avalanche Advisory for December 22, 2016

This advisory expires at Midnight tonight.

Huntington Ravine has CONSIDERABLE and MODERATE avalanche danger. Central, Pinnacle, Odell, South Gully and Escape Hatch have Considerable avalanche danger. Natural avalanches are possible and human-triggered avalanches are likely. North, Damnation, and Yale have Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible.

 Tuckerman Ravine has CONSIDERABLE and MODERATE avalanche danger. Sluice, The Lip, Center Bowl, Chute, Left Gully and Hillman’s Highway have Considerable avalanche danger. Natural avalanches are possible and human-triggered avalanches are likely. Lobster Claw and Right Gully have Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible. Lower Snowfields and Little Headwall are not rated due to a lack of snow.

Avalanche danger is Low early this morning but is rising, with natural and human-triggered avalanches becoming increasingly possible through the day.

AVALANCHE PROBLEM: Wind speed and direction today will effectively build wind slabs, particularly in our upper start zones. Look for cross-loaded slabs in other lee areas of terrain features due to the shift in the wind to the west in the early afternoon hours. Our danger rating today is straddling the line between moderate and considerable ratings due to a combination of factors. Count on having your terrain and snowpack assessment skills being thoroughly tested today.

WEATHER: As snows showers begin at this hour, WSW winds in the 40 mph range are starting to move snow into our forecast terrain. Weather models show a shift in wind direction through the west to the northwest through daylight hours with the wind ramping up a bit into the 35-50 mph range. These wind speeds will effectively move the forecasted 2-4” of snow from our fetch zone in the flat alpine terrain into avalanche terrain creating the potential for new wind slabs to form throughout the day. Anticipate reduced visibility and flat light to challenge route-finding and surface snow assessment.

SNOWPACK: We are starting the day with a porous icy melt/freeze crust on the surface. This crust is coarse enough to allow weak bonding initially in many areas of our terrain but is certainly not strong enough to support building slabs in place in all areas. Wind speeds are light enough currently that the snow falling early on should blanket the terrain. This new snow is likely to be the primary weak layer for wind slabs that will form on top through the day. Remember that the bed surface is hard and icy and will remain the primary travel surface until more snow falls. This fast sliding surface will make self-arresting extremely difficult whether caused by a slip and fall or a small avalanche sweeping you off your feet.

The Lion Head Winter Route is open and the most direct route to the summit. The Tuckerman Ravine Trail bridge is completed enough to allow traffic again so you can avoid the detour. Please be careful of construction debris near crossover 7 on the Sherburne Trail and watch out for machine traffic since the Tuckerman Ravine trail is still not really passable for snow machines. Thanks for your continued patience!

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 8:00 a.m., Thursday, December 22, 2016. A new advisory will be issued tomorrow.

Frank Carus, Snow Ranger
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2716

2016-12-22

Avalanche Advisory for Wednesday, December 21, 2106

This advisory expires at midnight.

All forecast areas in Huntington and Tuckerman Ravine have LOW avalanche danger. Natural and human-triggered avalanches are unlikely. Watch for unstable snow on isolated terrain features.

AVALANCHE PROBLEM: The avalanche problem will be Wind Slab today. These will be isolated pockets, tucked under or in lee areas of terrain features. With good visibility, these slabs will be easy to identify when compared next to the dirty melt/freeze surface. This old surface will be the source of the greatest hazard today, providing the potential for long, sliding falls. Using crampons and an ice axe effectively on moderate and steeper terrain today will be crucial.

WEATHER: After several days of clearer skies, summit fog and wind will return today. West winds will decrease slightly from the current 60mph, shifting to the SW overnight. While the fog may lift during the morning, expect diminished visibility today, particularly as moisture arrives in the afternoon. Up to 1” of upslope snow is called for today, with another trace to 1” tonight. By morning tomorrow, a clipper system will cruise through, bringing unsettled conditions and measureable snowfall.

SNOWPACK: Our current snowpack is dominated by the melt/freeze event that took place over last weekend. This surface layer is bridging weaknesses that may exist lower in the snowpack. It is also acting as the bed surface for future avalanches. The dusting of snow on Monday has left a few pockets of instability in the form of wind slabs. These will be easy to avoid by making safe travel decisions. If snow falls today, be on the lookout for these isolated pockets to grow in size, but still remain small. Reports of great alpine climbing abound due to the firm snow surface. Bear in mind that even a slope of moderate angle can lead to a sliding fall. These are the days when roping up in 3rd and 4th class terrain may seem like a sound solution. Quick and effective self arrest skills will be critical for travel in any steep open terrain.

The Lion Head Winter Route is open and the most direct route to the summit from the east side of the mountain. The bridge that is still under construction on Tuckerman Ravine Trail now allows traffic making this the preferred hiking route to gain elevation from Pinkham. Please be careful of construction debris near the top crossover when descending the Sherburne Trail and be on the lookout for heavy equipment as work continues.

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 8:00 a.m., Wednesday, December 21, 2016. A new advisory will be issued tomorrow.

Helon Hoffer, Snow Ranger
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2716

2016-12-21

Avalanche Advisory for Tuesday, December 20, 2016

This advisory expires at midnight.

All forecast areas in Huntington and Tuckerman Ravine have LOW avalanche danger. Natural and human-triggered avalanches are unlikely. Watch for unstable snow on isolated terrain features.

AVALANCHE PROBLEM: Today’s avalanche problem will be Wind Slab. These will likely be small, tucked under and behind terrain features, and easy to identify. However, with an icy surface underneath, even a small avalanche can create a significant hazard. This is due to the fact self-arresting on the slick surface will be next to impossible. Long, sliding falls are the main concern today. Crampons and an ice axe will be crucial to safe travel.

WEATHER: Unseasonably warm temperatures on Saturday night into Sunday brought along a half inch of rain. Following this, temperatures bottomed out at -16F and have now rebounded to more a more normal temperature of 7F. On Monday, the Summit recorded 0.2” of snow. Today will be clear with west winds starting at 30mph and increasing to 75mph through the day and night. We may see a dusting of snow tonight and possibly again tomorrow.

SNOWPACK: The warming and rain event allowed our snowpack to hit the reset button in terms of stability. While weak layers remain further down in the snowpack, it will be highly unlikely to impact them due to the bridging strength of the melt/freeze crust now bridging the surface of the snow. The dusting of snow on Monday was subjected to strong winds. Expect small, isolated pockets of newly formed wind slab to exist in lee areas. On previously wind scoured surfaces or impacted trails, the crusty surface will allow quick travel, provided you have crampons to bite into the snow and ice. Long, sliding falls are a distinct possibility today on steep surfaces. Even lower-angled surfaces can cause out-of-control slides for the unprepared. Below treeline and deep in the woods, this crust will provide postholing conditions that your shins will not let you forget. It may be a good day to rethink your bushwhack to Isolation.

The Lion Head Winter Route is open and the most direct route to the summit from the east side of the mountain. The Tuckerman Ravine Trail bridge is completed enough to allow traffic, so you can avoid the detour. Please be careful of construction debris near crossover 7 on the Sherburne Trail and some snow machine and snow tractor traffic as some final work for the season continues. Thanks for your continued patience!

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 8:00 a.m., Tuesday, December 20, 2016. A new advisory will be issued tomorrow.

Helon Hoffer, Snow Ranger
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2716

2016-12-20

Avalanche Advisory for Monday, December 19, 2016

This advisory expires at Midnight tonight.

All forecast areas in Huntington and Tuckerman Ravine have LOW avalanche danger. Natural and human-triggered avalanches are unlikely. Watch for unstable snow on isolated terrain features.

AVALANCHE PROBLEM: Around half an inch of rain yesterday has effectively reduced our avalanche problem to Low. If it wasn’t for the possibility of encountering some small wind slabs behind wind breaks, beneath steep features and cross-loaded in steep gullies, there would be no avalanche problem at all. Trace amounts of snow fell since our rain event have built these slabs. Even small avalanches can create problems on our icy bed surface. These should be easy to identify contrasted to the old darker, refrozen snow surface. Otherwise, your larger travel concerns today will be a wide variety of refrozen snow and icy surfaces.

WEATHER: After reaching a high temperature of 40F (4C) on the summit yesterday, we have returned to near seasonable temperatures this morning after a visit with -11F (-24C) last night. Some scattered clouds remain overhead but otherwise clear visibility and cold temperatures around 0F mark the start to the day. As high pressure continues to settle in, expect winds to slacken even further and shift west into the 25-40 mph (40-65 kph) range. Temperatures on the summit will continue to rise until they reach into the mid-single digits today and mid-teens tomorrow.

SNOWPACK: Time to put your skis away for bit and enjoy favorable ice climbing and mountaineering conditions. The nice dump of new snow that came on Saturday along with the rest on the above average December snowfall has been soaked and refrozen into a variably breakable ice crust. While you could pretty easily move around in most terrain last week without crampons, that is not the case today. Along with this refrozen surface comes the risk of long sliding falls on steep terrain so move carefully since self-arrest probably won’t work on a steep slope in these conditions. A breakable crust in the woods and on flatter terrain that wasn’t previously wind packed or scoured is likely to be breakable and at higher elevations that could be a real problem if you find yourself off-trail or on seldom traveled trails. Wallowing in deep snow beneath a breakable ice crust that scrapes the skin off your shins is no way to spend the day. As mentioned in the avalanche problem discussion, you’ll find some pockets of new wind slab.

The Lion Head Winter Route is open and the most direct route to the summit from the east side of the mountain. While not technically closed by law or Forest regulation, the Lion Head summer trail above Hermit Lake is threatened by several avalanche paths, making the Winter Route a better option when avalanche conditions exist. The Tuckerman Ravine Trail bridge is completed enough to allow traffic again so you can avoid the detour. Please be careful of construction debris near crossover 7 on the Sherburne Trail and some snow machine and snow tractor traffic as some final work for the season continues. Thanks for your continued patience!

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 7:45 a.m., Monday, December 19, 2016. A new advisory will be issued tomorrow.

Frank Carus, Snow Rangers
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2716

2016-12-19

Avalanche Advisory for Sunday, December 18, 2016

All forecast areas of Huntington and Tuckerman Ravine have CONSIDERABLE avalanche danger. Natural avalanches are possible and human triggered avalanches are likely. Dangerous avalanche conditions will exist today. Cautious route-finding and conservative decision making are essential. Little Headwall and Lower Snowfield are not forecast due to lack of snow.

AVALANCHE PROBLEM: Wet Slabs are the primary avalanche problem today. These are notoriously hard to predict and can range from small pockets to large and destructive avalanches. Wet slabs could occur in any of our avalanche paths and may release deep in the snowpack. There many variables that influence the release of these wet slabs. Whether the rain overwhelms the tensile and shear strength of our existing slabs, or percolates through to lubricate the melt-freeze crust or adjusts to the increased load without avalanching are all too complex to forecast with much certainty. Given the avalanche danger and the unsupportive walking or climbing surface, you might ask yourself why would you bother to enter avalanche terrain. With precipitation forecasted throughout the day, we may see a new layer of wind slab form on the refrozen snow pack. Also be aware of the potential for undermined snow, particularly if crossing streams or rivers.

WEATHER: If you dont like the weather, just wait five minutes. Arctic cold, snow, rain, 50 degrees, more snow, wind chill warnings. Enough said. Saturday began at -6F with 35mph W winds. Snow began to fall around 6am and continued until 3pm, delivering 6.5”, with the heaviest snowfall occurring around noon. This snow arrived on 30-55mph S and SW winds. By midnight, temps rose to 32F with steady 65mph W/WSW winds. Overnight and into this morning, the summit recorded steady rain and a further increase of temperatures. At 7am, the summit and Pinkham were at 39F with Hermit Lake at 49F. It looks like rain will continue this morning, transitioning to sleet, ice, and then back to snow as temperatures begin their plummet. By late-morning, we should see the summit drop below freezing with a steady decline to sub-zero by Monday.

SNOWPACK: Friday was the first day in over a week we recorded no new snow. Field time revealed crown lines and debris in both ravines. The 6.5” of snow that fell yesterday was subjected to good loading speeds throughout the afternoon. These west winds loaded the start zones of many of our forecast areas. Over the course of the night, these newly formed wind slabs were topped with .31” of rain. This is our first rain on snow event of the season, creating the potential for wet slabs which are next to impossible to predict their size and location. Our terrain has rapidly become connected over the past week creating the possibility of the something large coming off the Tuckerman headwall. Wind slabs that formed last night may have already avalanched in certain areas. I would be particularly suspect of slopes that did not avalanche yesterday as the rain soaks and further loads up an already unstable slab. With all this in mind, temperatures will drop today, refreezing this saturated snowpack. As this happens and things begin to lock up, we will see a stabilizing trend turning the surface of our snowpack into a rock hard surface. Travelers in the afternoon and evening should be prepared to use crampons and ice axes to prevent long sliding falls.

The Lion Head Winter Route is now open and the recommended route to the summit from Pinkham. While the construction on bridge on the Tuckerman Ravine Trail continues, the trail is open and the fastest route to Hermit Lake. Those on the Sherburne should be prepared to encounter construction equipment accessing the work site.

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 8:00 a.m., Sunday, December 18, 2016. A new advisory will be issued tomorrow.

Helon Hoffer / Frank Carus, Snow Rangers
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2716

2016-12-18

Avalanche Advisory for Saturday, December 17, 2016

This avalanche advisory expires at Midnight tonight.

Huntington Ravine has HIGH and CONSIDERABLE avalanche danger. Central, Pinnacle, Odell and South Gully have High avalanche danger. Natural avalanches are likely and human-triggered avalanches are very likely. North, Damnation, Yale, and Escape Hatch have Considerable avalanche danger. Natural avalanches are possible and human triggered avalanches are likely.

 Tuckerman Ravine has HIGH and CONSIDERABLE avalanche danger. Sluice, The Lip, Center Bowl, Chute, Left Gully and Hillmans Highway have High avalanche danger. Natural avalanches are likely and human-triggered avalanches are very likely. Lobster Claw and Right Gully have Considerable avalanche danger. Natural avalanches are possible and human triggered avalanches are likely. Lower Snowfields and Little Headwall are not rated due to a lack of snow though a portion of the Lower Snowfields could be struck by avalanche debris from Duchess.

Very dangerous avalanche conditions will exist in both Ravines today.

AVALANCHE PROBLEM: 4-8” of new snow on increasing winds will build dangerous wind slabs today. Wind loading will form cohesive, unstable slabs of snow on top of softer, cold dry snow deposited by diminishing winds yesterday. Many avalanches paths ran in the past 36 hours and then reloaded so anticipate larger avalanches in some locations that will run further onto the floor than you might expect. The floor of Tuckerman Ravine would not be a good place to travel today. Several “red flags” exist today that will challenge even the most advanced avalanche practitioner so think hard if you want to try to outsmart the avalanche problem.

WEATHER: Winds currently from the southwest in the relatively light 35 mph range will increase and shift west this afternoon. This shift and increase in velocity to the 40-55 mph range will mark the transition to our peak natural avalanche potential. Gusts reaching 65 mph may transport enough snow today prior to the main shift in speed and direction. We are starting the day at 0F on the summit though temperatures will reach 20F or so by dark.

SNOWPACK: Clear visibility yesterday afternoon gave us a brief opportunity to observe signs of widespread avalanche activity in both Ravines. Yesterday’s avalanches appeared to be small to medium sized (R1-3) but I doubt that will be the case later today and tonight if the precipitation and wind forecast plays out. Our slopes and gullies have grown quite a bit since the start of the month, with avalanche debris stretching further down into the avalanche paths after each cycle. We have had very cold temperatures over the past few days which has not helped with snow settlement and may have even driven a faceting process near the deep ice crust that exists in some shady aspects. If venturing into the terrain today, know that poor visibility due to fog and blowing snow will challenge assessment and safe travel techniques. Upper start zones may be very different than the snow that you are traveling on below. For this reason, I would stay out of the path of any open slope or gully. A complex snowpack and multiple red flags will make it a good day to avoid avalanche terrain altogether.

The Lion Head Winter Route is open and the most direct route to the summit. The Tuckerman Ravine Trail bridge is completed enough to allow traffic again so you can avoid the detour. Please be careful of construction debris near crossover 7 on the Sherburne Ski Trail. Thanks for your continued patience!

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 8:05 a.m., Saturday, December 17, 2016. A new advisory will be issued tomorrow.

Frank Carus, Snow Ranger
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2716

2016-12-17

Avalanche Advisory for Friday, December 16, 2016

This advisory expires at Midnight.

Huntington Ravine has CONSIDERABLE and MODERATE avalanche danger. Central, Pinnacle, Odell and South Gully have Considerable avalanche danger. Natural avalanches are possible and human-triggered avalanches are likely. North, Damnation, Yale, and Escape Hatch have Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible.

 Tuckerman Ravine has CONSIDERABLE and MODERATE avalanche danger. Sluice, The Lip, Center Bowl, Chute, Left Gully and Hillmans Highway have Considerable avalanche danger. Natural avalanches are possible and human-triggered avalanches are likely. Lobster Claw and Right Gully have Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible. Lower Snowfields and Little Headwall are not rated due to a lack of snow.

AVALANCHE PROBLEM: Another 1.4” of snow in the past 24 hours, along with wind speeds that continue to increase, keep natural, wind slab avalanches possible. These wind slabs are likely to be stubborn in most places but could likely be triggered by someone traveling over the right thin spot or weak layer in the slab. These hard slabs could run out pretty far given that a regular series of avalanche cycles has smoothed out and extended many of our avalanche paths. That said, many boulders and cliffs remain uncovered so even a small avalanche would be really unforgiving in areas like Sluice, Lip, Center Bowl and Hillmans whose paths are peppered with boulders. We are teetering on the edge of possibility for natural avalanche activity and may very well be scoured and wind packed into a more Moderate hazard especially by the end of the day.

WEATHER: The temperature will fortunately rebound from where it sits at -35F at 6am. Winds from the WNW in the 70-90 mph range may gust to 105 mph this morning and abate some today and shift a bit west. 50-70 mph later with temperatures in the -15F range will still present plenty of opportunities to freeze fingers while digging your stability test pits and frostbite your cheeks looking for a line around potentially unstable smooth pillows of wind slab.

SNOWPACK: We have a dynamic snow pack right now and have had limited opportunities to move around with an acceptable degree of safety over the last couple of days. We do know a few things based on our snowpack and weather history. Pencil hard wind slabs are likely to be pretty widespread. In some places where they are thick and bridge between gully walls or lower angled terrain they are likely to be unreactive. In unsupported, steeper or convex areas, the strain on the slab combined with the presence of weak layers of rimed particles, or possibly the melt-freeze crust, may yield the right ingredients for a hard slab avalanche. Deep slabs at the base of steep pitches of ice, such as the approach to Pinnacle, have proven to be a problem under similar conditions too. Be heads up if you venture into the terrain since lots of challenges are in play.

The Lion Head Summer Trail remains the better route to the summit. Remember that the bridge work continues on the Tuckerman Ravine Trail so use the detour on the Huntington Ravine Trail. Many people are using the Sherburne as an uphill route; please be on the lookout for these people as well as machinery that is using the Sherburne as the access to the construction site. We hope to reopen the Tuckerman Ravine trail today so look for signs being pulled by FS staff!

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 7:30 a.m., Friday, December 16, 2016. A new advisory will be issued tomorrow.

Frank Carus, Snow Ranger
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2716

2016-12-16

Avalanche Advisory for Thursday, December 15, 2016

This advisory expires at Midnight tonight.

Huntington Ravine has CONSIDERABLE and MODERATE avalanche danger. Central, Pinnacle and Odell Gully have Considerable avalanche danger. Natural avalanches are possible and human-triggered avalanches are likely. North, Damnation, Yale, South and Escape Hatch have Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible.

Tuckerman Ravine has CONSIDERABLE and MODERATE avalanche danger. The Lip, Center Bowl, Chute, Left Gully and Hillmans Highway have Considerable avalanche danger. Natural avalanches are possible and human-triggered avalanches are likely. Lobster Claw and Right Gully have Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible. Lower Snowfields and Little Headwall are not rated due to lack of snow.

AVALANCHE PROBLEM: New snow yesterday, combined with the potential for new snow today on increasing wind speeds from the west, will build wind slabs. These wind slabs have the potential to be sensitive to human triggering as well as to increased loading. Travel in avalanche terrain will be further complicated by poor visibility. A melt freeze crust on old bed surfaces with associated facets in shady aspects is also a concern. We have a dynamic snowpack right now and with rapidly changing weather today, would be travelers in our terrain would be hard-pressed to do so safely. These avalanches most likely won’t be large in most areas but the runouts are particularly unforgiving right now with boulders, cliffs and stout bushes making any avalanche potentially dangerous.

WEATHER: Over the past 36 hours, wind speeds have been relatively light and have loaded in 4” of low density snow. Today, a trough may continue to send potentially heavy snow squalls in our direction from the Great Lakes. The rate of snowfall this morning indicates that we will soon reach or exceed the NWS forecast of 1-2” and the MWObs forecast of a trace to 1”. Though these amounts don’t seem like much, history as shown that a smooth fetch zone in the alpine zone can give up this snow to the wind and rapidly build sizable wind slabs. As winds increase today, snow will become more densely packed (lots of Tuckerman terrain) or scoured out (northern Huntington gullies) but not before passing through peak probability of natural and human triggering. Temperatures will continue down to -20’s F below zero.

SNOWPACK: Some snow that survived warm November conditions was coated by the widespread snow/rain slush mix that now coats everything at higher elevations, including some older snow in shady aspects on the lookers left of both Ravines.  This month, the summit has recorded 52” of snow which is roughly twice the normal amount. Only a few brief spells of hurricane force winds have pummeled and scoured our snowpack which has contributed to our protracted spell of elevated avalanche danger. Multiple avalanche cycles have occurred, mostly in the upper layers of the snowpack. A lingering concern for me now is the buried melt/freeze crust that exists in those shady, more continuous and larger slopes with the oldest bed surfaces, primarily Center Bowl, Chute and Left. Cold temperatures tell me it is probably faceting in some areas. That said, the primary concern remains new wind slabs from todays squalls and increasing wind.

The Lion Head Summer Trail remains the better route to the summit. Remember that the bridge work continues on the Tuckerman Ravine Trail so use the detour on the Huntington Ravine Trail. Many people are using the Sherburne as an uphill route; please be on the lookout for these people as well as machinery that is using the Sherburne as the access to the construction site. We hope to reopen the Tuckerman Ravine trail soon. Thanks for your continued patience.

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 8:00 a.m., Thursday, December 15, 2016. A new advisory will be issued tomorrow.

Frank Carus, Snow Ranger
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2716

2016-12-15

Photo Condition Update

Huntington Ravine

December 13, 2016

pinnacle-and-central

Looking up into the fan of Huntington. You may even be able to see climbers topping out Cloudwalkers.

 

odell

Notice the enlarged snowfield below the ice in Odell. Still a bit bony in the upper reaches.

 

south-adn-odell

South Gully is almost snow from top to bottom. Still pretty thick down low.

 

Tuckerman Ravine

December 13, 2016

lobster-claw

Still very early season in Lobster Claw.

 

bowl-with-crown

The Bowl. Things to notice besides my thumb: The crown in the bottom left of the photo continues over to lookers left under the Chute and is rapidly filling in. Also, while the center Headwall looks blurry, it is from the blowing snow pouring down over the ice.

 

left

Left Gully and the Chute looking much larger than last year in mid-December.