Avalanche Advisory for Friday, April 8, 2016

Tuckerman Ravine has MODERATE avalanche danger. Natural avalanches are unlikely and human-triggered avalanches are possible in all forecast areas. Evaluate snow and terrain carefully. Lobster Claw, Little Headwall and Lower Snowfields are not posted due to lack of snow.

Huntington Ravine is under a General Bulletin. You will need to do your own snow stability assessments when traveling in avalanche terrain in Huntington. A danger of falling ice exists, and will persist until it all comes down.

AVALANCHE PROBLEM: Today’s avalanche problem will be in the form of wind slabs. Snow shower activity this morning, coupled with upslope snow showers this afternoon, may produce 2-4” of snow. This new snow will be falling on a refrozen rain crust with wind speeds in the 30-45mph range. Wind slabs sensitive to human-triggering may form in lee areas of a southwest wind and crossload in other areas. If wind and snow remain on the lighter side, expect only pockets of unstable snow. Snow totals near 4” with wind speeds at the upper end of the forecast velocity could develop larger areas of wind slab that will be harder to avoid.

WEATHER and SNOWPACK: There will be lots of refrozen old surface in our terrain due to the heavy rain that ended early this morning.  This storm dumped 2” (52mm) of rain at Hermit Lake with 1.12” rain and a mixed bag of frozen forms of sleet and wet snow on the summit. Streams are raging with snowmelt and though there is little in the way of visibility this morning, it is likely that the waterfall holes in the Lip are showing like gaping wounds. Clearly our already meager snowpack has taken another beating as evidenced by 12cm of settlement at the Hermit Lake snow stake since Tuesday. Today winter will begins its steady march back into the region with temperatures on a steady decline that will lock up our deeper snowpack and throw away the key for the weekend. Temperatures will reach down to the mid-teens later today and just above 0F overnight. Snow showers have begun at Hermit Lake this morning with lots of snow shower activity moving our way on the radar. Clouds and snow showers will reduce visibility and flatten out the light. I don’t expect you’ll find good skiing on stable snow today considering that the total snowfall amounts are unlikely to bury the icy bed surface enough to resist being scraped off during a turn. Other hazards you’ll encounter today include:

  • Long sliding falls – Crampons are highly recommended in steep terrain. Snowshoes and microspikes are no substitute. Expect a variable snowpack with some new snow falling on a firm surface with limited boot penetration. Arresting a fall on a steep slope can be practically impossible, even with an ice axe.
  • Crevasses, moats and waterfall holes – Warm water flowing under the snow pack creates holes and thin spots in surface that are deep enough to injure or kill you. New snow can drift and obscure the openings.

The Sherburne Ski Trail is now closed at #7, allowing about 2/3 mile of skiing from Hermit Lake. Expect exposed ice. The Harvard Cabin is closed for the season. The only camping permitted in the Cutler River Drainage on the east side of the mountain will be at Hermit Lake Shelters.

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.
  • Posted 8:30 a.m., Friday, April 8, 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

2016-04-08

Avalanche Advisory for Thursday, April 7, 2016

Tuckerman Ravine has MODERATE avalanche danger. Natural avalanches are unlikely and human-triggered avalanches are possible in all forecast areas. Evaluate snow and terrain carefully. Lobster Claw, Little Headwall and Lower Snowfields are not posted due to lack of snow.

Huntington Ravine is under a General Bulletin. You will need to do your own snow stability assessments when traveling in avalanche terrain in Huntington. A danger of falling ice exists, and will persist until it all comes down.

AVALANCHE PROBLEM: Several potential avalanches problems are in the mix today. This morning, there is a Low danger in the pockets of wind slab which developed on Tuesday. These are scattered in the steepest areas sheltered from a west wind like beneath the ice in the Lip and Center Bowl and in the mid sections of Chute and Left. Later today, it will become more possible to trigger these slabs as temperatures warm and rain falls. More wind slabs may develop on a south wind, this morning through mid-day, if new snowfall persists before changing over to rain. Anticipate the small pockets of older wind slab and any newer wind slabs developing today to become a wet slab/wet loose problem late in the day and overnight as heavy rain develops.

WEATHER: Mountain weather is warming to more seasonable temperatures just long enough for 1-2” of rain to fall today through the overnight. Some new snow and sleet will fall prior to this changeover, though with 4300’ temperatures already at 31.7F at 7:10am, it seems as though the period of snow and mixed precipitation will be short-lived and perhaps occur only at the very highest elevations above our avalanche terrain. Expect a return to winter-like weather tomorrow with upslope snow showers and temperatures falling through the day, ultimately bottoming out in the single digits Friday night. Southerly winds, in the 40-50mph range to start, will shift west later today or this evening and ramp up to the 55-75mph range on the summit. Overall, expect an unpleasant brush with hypothermia if you head into the hills today.

Heavy rain will advance the spring hazards of undermined snow, waterfall blowouts and icefall until cold temperatures return tomorrow. In addition to treacherous wall-to-wall ice as you gain elevation on the Tuckerman Ravine and other trails, be aware of the following hazards and more today and through the weekend:

  • Long sliding falls – Crampons are highly recommended in steep terrain. Snowshoes and microspikes are no substitute. Expect a variable snowpack due to rain falling on a mostly firm surface with little boot penetration. Arresting a fall on an icy 30+ degree slope can be practically impossible, even with an ice axe. Refrozen snow and this sliding fall hazard will return with a vengeance after today’s warm
  • Crevasses, moats and waterfall holes – Warm water flowing under the snow pack creates holes and thin spots in surface that are deep enough to injure or kill you. New snow can drift and obscure the openings.
  • Falling ice – The best thing you can do is reduce your exposure by limiting the time you spend downslope from frozen waterfalls. Falling ice chunks can move with surprising speed and follow unpredictable trajectories. Colder temperatures following this warm up will reduce the likelihood of this hazard.

The Sherburne Ski Trail is now closed at #7, allowing about 2/3 mile of skiing from Hermit Lake. Expect exposed ice with new snow. The Harvard Cabin is closed for the season. The only camping permitted in the Cutler River Drainage on the east side of the mountain will be at Hermit Lake Shelters.

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.
  • Posted 8:00 a.m., Thursday, April 7, 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

2016-04-07

Avalanche Advisory for Wednesday, April 6, 2016

This advisory expires at Midnight

Tuckerman Ravine has MODERATE avalanche danger. Natural avalanches are unlikely and human-triggered avalanches are possible. Heightened avalanche conditions exist on specific terrain features.  Be sure to evaluate snow and terrain carefully to identify areas of concern. Lobster Claw, Lower Snowfields and Little Headwall are not posted due to lack of snow. Huntington Ravine is posted under a General Bulletin for the remainder of the season. You will need to do your own snow stability assessments when traveling in avalanche terrain in Huntington Ravine. A danger of falling ice exists, and will persist until it all comes down.

AVALANCHE PROBLEM: Today’s avalanche problem continues to be Wind Slab.  The 5-6″ (12.5-15cm) of low density snow that fell on Monday was delivered on moderate winds allowing for widespread wind slab to develop. Expect the most sensitive wind slabs to human triggers to be in the strong lee of mid-elevation Ravine terrain features such as under the Lip, under the Headwall, and above the narrows in the Chute

WEATHER: Through snowfall on Monday temperatures remained cold.  This trend has continued since snow ended Monday evening keeping the mercury below zero F on the summit of Washington. (BBBRRRR! Ah the variability of April!)  Today, temperatures will rise substantially, albeit only into the mid-teens F, as the next weather maker approaches, potentially delivering light snow by very late in the day.  This precipitation will transition through a variety of types overnight and through Thursday.  At some point tomorrow expect rain on Wind Slabs before moving back to snow Thursday night.  This forecasted 1.0-1.3″ of total melted liquid may fall heavy at times as snow, sleet, freezing rain, and rain so anticipate a messy day tomorrow.

SNOWPACK: 8.1″ of new snow fell on the summit between Saturday and Monday. The majority of this fell on Monday as 3% low density snow, on a shifting moderate summit wind, between 20-35mph. In protected lee areas of W and NW winds expect the initial low density snow to act as the weak layer for slab that built later in the snowfall event, and into Tuesday as winds increased. Although the summit was in the clear by yesterday’s maximum wind period, an afternoon peak of 73mph influenced many of the aforementioned protected areas to some degree.  Therefore, expect slabs of increased density over areas of lower density slab, some of which may be quite sensitive to human triggers.  Due to the low density Monday snow, and the varying degree of terrain influences, be prepared for a high degree of weakness variability.  Based on your stability tests you may feel comfortable traveling in new snow, but be careful moving into unrecognized dramatically weaker snow where it was less influenced by winds, such as close to dominate terrain features.  I.e. buttresses, the main Headwall, rollovers such as the Lip, etc. The cold temperatures has kept snow pack consolidation and stabilization slow.  So although you notice we have dropped the danger rating from yesterday, this is mostly due to the natural avalanche potential falling from possible to unlikely.  Today’s Moderate danger rating, having just crept below the Considerable line, still has a fair amount of concern for human triggers.  Evaluate snow and terrain carefully and be quite wary of others in the terrain that may trigger slabs above you or propagate over to your location.  Also think about what runout paths you are in as you consider wandering up the Tuckerman floor.

The same winds that loaded our terrain with snow have also scoured some areas, leaving the old rain crust visible. Arresting a fall on this hard layer of icy snow will be next to impossible. Long sliding falls can be disastrous, particularly if they take place above a rocks or an open crevasse. The Sherburne Ski Trail is now closed about a third of the way down. Please cross back over to the hiking trail at the rope and walk to Pinkham.  Expect new snow to hide vast amounts of water ice on the hiking trail. The Harvard Cabin is closed for the season. The only camping permitted on the east side of Washington in the Cutler Drainage is at Hermit Lake Shelters.

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.
  • Posted 7:00 a.m., Wednesday, April 6, 2016. A new advisory will be issued tomorrow.

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

2016-04-06

Avalanche Advisory for Tuesday, April 5, 2016

This advisory expires at 12:00 midnight.

Tuckerman Ravine has CONSIDERABLE and MODERATE avalanche  danger. Right Gully and Hillman’s Highway have Moderate avalanche danger. Natural avalanches are unlikely and human-triggered avalanches are possible. All other forecast areas of Tuckerman Ravine have CONSIDERABLE avalanche danger. Natural avalanches are possible and human-triggered avalanches are likely. Careful snowpack evaluation, cautious route-finding and conservative decision-making are essential. Lobster Claw, Lower Snowfields and Little Headwall are not posted due to lack of snow.

Huntington Ravine is under a General Bulletin. You will need to do your own snow stability assessments when traveling in avalanche terrain in Huntington. A danger of falling ice exists, and will persist until it all comes down.

AVALANCHE PROBLEM: Today’s avalanche problem is Wind Slab. Wind slab and avalanche danger will build throughout the day as winds increase. This wind slab will develop on very light density snow and is likely to be touchy even in Moderate rated areas. As the day progresses and loading continues, the likelihood of a naturally occurring avalanche and the potential size of an avalanche will increase, particularly in Considerable rated areas. Entering the floor of the ravine today will potentially put you in the path of avalanches.

WEATHER: Temperatures 15-20F below normal the past several days brought wintry conditions back to the mountain. The summit recorded 8″ (20cm) of snow over the past three days with 4.7″ (12cm) of that total yesterday. Hermit Lake received 6” (15.5cm) yesterday. Winds somewhat dampened yesterday as well as shifted to NNW, and now out of NW. High pressure will sweep in today, allowing skies to clear. Temperatures will remain cold and winds will increase to 50mph+ (80kph) by the end of the day.

SNOWPACK: Small accumulations of snow each of the past three days have allowed wind slabs to gradually increase in size. Throughout the day yesterday, very light 3% density snow fell on W shifting NW winds of 20-35mph. With winds increasing through the day today to ideal loading direction and speed, new wind slab will form and grow in size and thickness with an upside down configuration due to increasing winds. These slabs will be touchy to human triggers and may naturally release by this afternoon. While wind slab formed on Sunday will be stubborn to trigger by a human, it is possible for an avalanche in the newly formed wind slab to step-down into this older layer, dramatically increasing consequences. Traveling in avalanche terrain today will require careful snowpack evaluation.

The same winds that loaded our terrain with snow have also scoured several areas, leaving the old rain crust visible. Arresting a fall on this hard layer of icy snow will be next to impossible. Long sliding falls can be disastrous, particularly if they take place above a rocky run out or an open crevasse.

The Sherburne Ski Trail is now closed at #7, allowing about 2/3 mile of skiing from Hermit Lake. Expect exposed ice with new snow. The Harvard Cabin is closed for the season. The only camping permitted in the Cutler Drainage will be at Hermit Lake Shelters.

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 8:45 a.m., Tuesday, April 5, 2016. A new advisory will be issued tomorrow.

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

2016-04-05

Avalanche Advisory for Monday, April 4, 2016

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

Huntington Ravine is under a General Bulletin. You will need to do your own snow stability assessments when traveling in avalanche terrain in Huntington. A danger of falling ice exists, and will persist until it all comes down.

AVALANCHE PROBLEM: Hard, icy snow surfaces dominate the terrain but firm wind slabs lurk in lee areas of a west wind from the 3”+ of snowfall over the past 36 hours. These wind slabs were built by high winds in the 70mph range and though they will be stubborn, they could fail in the steepest terrain. New snow falling today on diminishing wind speeds is unlikely to produce significant stability issues unless totals exceed forecast amounts. The new snow will make visual assessment and route-finding around unstable pockets of wind slab more challenging.

WEATHER: Winter has returned to the mountain with temperatures well below normal for this time of year. Unfortunately for snow sports enthusiasts, the latest low pressure system to pass through the region is once again missing us. We may receive up to two inches today, an amount which may freshen things up a bit but which is far below the amount needed to bring us back to normal snowfall levels. Expect another frigid day on the hill with a high temperature reaching to 6F from the current -6F on the summit. Winds will diminish from the 40 mph range and shift to the northwest from the west, ultimately blowing in the 10-25mph range on the summit.

SNOWPACK: Spatial variability will be the name of the game today. Those venturing into avalanche terrain will find a mixture of wind-scoured rain crust and firm, textured wind slab of varying thicknesses, all composed from snow and strong winds since Saturday evening. Slopes scoured by these winds will be penetrable only by crampons and an ice axe and be nearly impossible to self-arrest on. Areas that were not scoured likely contain firm wind slab that will be stubborn to trigger. The problem area for these wind slabs is often on its edge. As the slab thins, it may be possible for a human’s weight to affect a weakness in the slab. Beware of the transitions when moving from old surface to the pockets of wind slab.

The Sherburne Ski Trail is now closed at #7, allowing about 2/3 mile of skiing from Hermit Lake. Expect ice with a dusting of new snow. The Harvard Cabin is closed for the season. The only camping permitted in the Cutler Drainage will be at Hermit Lake Shelters.

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.
  • Posted 7:40 a.m., Monday, April 4, 2016. A new advisory will be issued tomorrow.

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

2016-04-04

Avalanche Advisory for Sunday, April 3, 2016

This advisory will expire tonight at 12:00 midnight.

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

Huntington Ravine is under a General Bulletin. You will need to do your own snow stability assessments when traveling in avalanche terrain in Huntington. A danger of falling ice exists, and will persist until it all comes down.

AVALANCHE PROBLEM: Today’s primary avalanche problem will be isolated pockets of wind slab. These pockets will likely be small and located in sheltered lee areas, like the Chute, Center Bowl and Lip, as well as the start zones of Left Gully and Hillman’s Highway. Winds will increase through the day, reaching the century mark around dark. As this happens, these pockets will reach peak sensitivity mid t0 late morning and then increase in strength as winds grow stronger. Many areas will be scoured to old surface. Safe travel will be difficult today as blowing snow and fog will make constant whiteout conditions.

WEATHER: Cold temperatures yesterday prevented any softening of the snowpack. Around dusk last night, the summit received 1.3″ (3.3cm) of new snow with Hermit Lake recording the same. Through the night, temperatures fell and winds increased to current summit conditions of 1F (-17C) and 51mph (82kph) winds. Winds are forecasted to increase steadily through the day, gusting to 130mph (209kph) by dusk. We may receive another trace to 2″ of snow today.

SNOWPACK: New snow yesterday evening fell on a well-frozen snowpack. Much of the new snow was heavily-rimed graupel and fell on lighter winds. Combine these factors with a denser slab forming due to increasing winds and we have a classic avalanche problem. However, only 1.3″ of new snow is available for transport. This morning, before winds really ramp up, I see the potential for isolated pockets to be reactive to a human trigger. As winds increase, these pockets will be hammered into very hard slabs, becoming less reactive. The potential for an additional 2″ of snow exists, but forecasts are leaning towards low accumulations. Safe travel in avalanche terrain today will require good visuals to see where pockets are developing and where winds are scouring down to the old surface. Due to blowing snow and cloudy conditions, visuals will be hard to acquire making travel difficult today.

Spring hazards you need to know about include:

  • Very icy conditions make any slips or falls in steep terrain a very dangerous event. Stopping a fall can be near impossible on hard refrozen rain crusts. Using crampons and and an ice axe is helpful, but not foolproof. The best way to mitigate this hazard is to avoid steep icy slopes, i.e. wait for a better day to get into steep terrain.
  • Crevasses, moats and waterfall holes – Multiple waterfall holes have opened in the Lip, including the open book hole responsible for a hiker fatality April 1, 2012, but they may be hidden from view by newly wind loaded snow. In other areas, large volumes of water is flowing under the snow pack, which has created small holes or thin snow bridges.

The Sherburne Ski Trail is now closed at #7, allowing about 2/3 mile of skiing from Hermit Lake. Expect ice with a dusting of new snow.

The Harvard Cabin is closed for the season. The only camping permitted in the Cutler Drainage will be at Hermit Lake Shelters.

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.
  • Posted 8:30 a.m., Sunday, April 3, 2016. A new advisory will be issued tomorrow.

Helon Hoffer and Jeff Lane, Snow Rangers
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2716

2016-04-03

Avalanche Advisory for Saturday, April 2, 2016

This advisory will expire tonight at 12:00 midnight.

All forecast areas of Tuckerman Ravine have Low avalanche danger. Natural and human-triggered avalanches are unlikely. If new snow arrives, watch for unstable snow in isolated pockets late in the day.

Huntington Ravine is under a General Bulletin. You will need to do your own snow stability assessments when traveling in avalanche terrain in Huntington. A danger of falling ice exists, and will persist until it all comes down.

AVALANCHE PROBLEM: To start the day, the snowpack is very stable and avalanche danger is virtually nonexistent. If the mountain receives the upper range of snow forecast for today (2″ or 5cm), new wind slab may develop in sheltered lee areas, such as under the ice in the headwall or up in the Lip. Any new slabs will be forming on an icy rain crust and might be sensitive to triggering. With this said, late in the day is when these problems will be developing. Pay attention for new snow accumulations throughout the day and expect instability if you find pockets of new deposits of windblown snow.

WEATHER: Yesterday was a very warm and rainy day, reaching 43F at the summit and even warmer at lower elevations. The summit reported 0.43″ (17mm) of rain, while at Hermit Lake we measured .28″ (7mm). Overnight temperatures dropped down below freezing at all elevations except for the very bottom of the mountain. The temps are unlikely to rebound more than a few degrees, so you should expect cold conditions and a frozen snowpack. We might see an inch or two of snowfall today, the best chance for this is in the afternoon or evening, and 1-3″ more snow in the overnight hours.

Spring hazards you need to know about include:

  • Very icy conditions make any slips or falls in steep terrain a very dangerous event. Stopping a fall can be near impossible on hard refrozen rain crusts. Using crampons and and an ice axe is helpful, but not foolproof. The best way to mitigate this hazard is to avoid steep icy slopes, i.e. wait for a better day to get into steep terrain.
  • Crevasses, moats and waterfall holes – Multiple waterfall holes have opened in the Lip, including the open book hole responsible for a hiker fatality April 1, 2012. In other areas, large volumes of water is flowing under the snow pack, which has created small holes or thin snow bridges.
  • Falling ice – The best thing you can do is reduce your exposure by limiting the time you spend downslope from frozen waterfalls. Falling ice chunks can move with surprising speed and follow unpredictable trajectories. Cold weather decreases the likelihood of falling ice and rocks.

The Lion Head Winter Route is closed. Please use the Summer Lion Head Trail. The Sherburne ski trail is closed in the lower half. Please respect the trail closure and walk down the hiking trail.

The Tuckerman Ravine Trail from Pinkham to Hermit Lake is wall-to-wall water ice for long stretches. Please do not attempt this trail without some sort of traction device for your feet. The options for skirting around the ice are very, very limited.

Tonight is the last night for camping at the Harvard Cabin this season. They will be locking up Sunday morning. The only camping permitted in the Cutler Drainage will be at Hermit Lake Shelters.

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., Saturday, April 2, 2016. A new advisory will be issued tomorrow.

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

04-02-2016

Weekend Update – April 1, 2016

Avalanche Advisory for Friday, April 1, 2016

Tuckerman Ravine has MODERATE and LOW avalanche danger. The Lip and Center Bowl have Moderate avalanche danger. Natural avalanches are unlikely and human-triggered avalanches are possible. All other forecast areas in Tuckerman Ravine have Low avalanche danger with natural and human triggered-avalanches being unlikely. Lobster Claw, the Lower Snowfields, and Little Headwall are not posted due to a lack of snow in these areas.

Huntington Ravine is under a General Bulletin. You will need to do your own snow stability assessments when traveling in avalanche terrain in Huntington. A danger of falling ice exists, and will persist until it all comes down.

AVALANCHE PROBLEM: A remote threat of Wet Slab avalanches is the primary avalanche concern due to rain further saturating our snowpack or waterfalls spilling out of their channels and into the snow. Heavy rain during potential thunderstorm activity combined with runoff from prolonged melting, could lead to a waterfall blowout from one of the larger drainages. It would be worth reducing time spent in Sluice through Chute in Tuckerman Ravine, along with the floor of the Ravine, despite the low likelihood of a wet slab avalanche. Wet loose sluffing could also be a problem on steeper slopes.

WEATHER & SNOWPACK: New snow that fell early this week has settled during the past 48 hours of warm weather, leading to reduced stability concerns. Prolonged high winds cresting at 133 mph from the west early Wednesday morning scoured most of Huntington Ravine and deposited hard wind slabs in strong lee areas. Warm temperatures yesterday softened snow on all aspects and lead to further settlement with no reported avalanche activity. Shockingly warm temperatures overnight have continued the melting and settlement trend reducing our stability concerns to pockets of untouched newer wind slabs from Tuesday along with the melt water induced wet slab mentioned above. An active weather pattern starts today with the first of several cold fronts swinging through, spawning rain showers and even some thunderstorm activity midday with .6” forecast by nightfall. Temperatures will drop below freezing overnight with showers of rain changing to snow.

Spring hazards you will most likely encounter given today’s weather forecast include:

  • Crevasses, moats and waterfall holes – Water flowing under the snow pack creates holes and thin spots in the snowpack above which can be deep enough to injure or kill.
  • Falling ice – This one is unpredictable. The best thing you can do is reduce your exposure by limiting the time you spend downslope from frozen waterfalls. Falling ice chunks can move with surprising speed and follow unpredictable trajectories. Rain increases the likelihood of falling ice and rocks.

The Lion Head Winter Route is closed. Please use the Summer Lion Head Trail.

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., Friday, April 1, 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

2016-04-01