Avalanche Advisory for Monday, 4-16-2012

This advisory expires at midnight, April 16, 2012

Tuckerman Ravine has Moderate and Low avalanche danger. The Sluice, Lip, and Center Bowl have Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible. All other forecast areas in Tuckerman have Low avalanche danger. Natural and human triggered avalanches are unlikely. Huntington Ravine is under a General Advisory. You will need to do your own snow stability assessments when using avalanche terrain in Huntington. A danger of falling ice exists, and will persist until it all comes down.

Wow, I thought Sunday was warm, but it’s already warmer on the summit today than it got to all day yesterday, and it’s not even 7am yet. The intense heat the mountain will see today will create some hazardous conditions, and I’m not just talking about sunburn and dehydration. Avalanches, crevasses, undermined snow, and falling ice should be on your mind as you travel through the ravines. If you are looking to get off the beaten path, you’ll likely find deep wet snow, saturated with water and completely unsupportive. Yesterday in Tuckerman there were a handful of loose wet snow avalanches. A couple were triggered by falling ice in the Sluice, and the debris from one buried the top of Lunch Rocks where several people had been lounging around just one day earlier. Today you can expect similar types of loose wet avalanches. With early cloud cover, heating will be more evenly distributed, so the hazard won’t be driven entirely by the slope’s aspect relative to the sun. As clouds clear in the afternoon, the solar energy will certainly intensify heating on the south-facing slopes, increasing the potential for this to take place. This type of avalanche is different from the more typical slab avalanche, whether dry or wet slabs. While a large one can definitely produce enough debris to bury a person, the greater problem is related to the weight of the wet snow. The stuff is so incredibly heavy that it can easily sweep you off your feet. I would expect to see the majority of these today to be from the Center Bowl, Lip, and Sluice. I also believe there may be a slight chance that the snowpack will remain cohesive enough to propagate a slab avalanche, but I feel the likelihood is low enough for the current ratings to best describe the overall avalanche potential. Remember, just because it’s mid-April does not mean you should ignore the red flags of avalanche danger, such as rapid or prolonged warming.

Falling Ice will happen today; I’m willing to bet on it. It is important that you recognize this hazard and take steps to avoid being underneath ice when it falls. The greatest icefall hazard exists from the Center Headwall and the Sluice ice above Lunch Rocks, though yesterday we saw ice falling in Left Gully, the Chute, and Right Gully as well! Icefall can happen fast and can be enormous, shattering ice in multiple directions. Lunch Rocks is not be considered a safe place to be. Regardless of where you are, you should always be looking uphill and thinking about what might fall from above…ice, avalanches, dropped snowboards, people without crampons, etc. can quickly turn a great day into a disaster.

The Center Bowl and Lip area have numerous deep crevasses from earlier warm weather that is now hidden by new snow. Currently, you cannot see where these are, so you will not be able to assess the hazard safely without roping up and probing ahead. Because the consequences of falling into one of these crevasses are severe we recommend avoiding this area entirely. There are some smaller crevasses outside of the Lip and Center Bowl area, and underneath the Sluice ice is another area where we historically have seen very dangerous undermined snow and crevasse hazard.

Hikers should not plan to use the Tuckerman Ravine Trail to climb to or descend from the alpine zone and the summit of Mt. Washington. From Pinkham, Lion Head and Boott Spur are much better options. The John Sherburne Ski Trail is currently open about halfway down. We expect the skiable terrain to be shortened by tomorrow.

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 Pinkham Notch Visitor Center, or the caretakers at Hermit Lake Shelters. 
  • 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

2012-04-16

2012-04-16 Wet loose debris on Lunch Rocks

Avalanche Advisory for Sunday, 4-15-2012

This advisory expires at Midnight, April 15, 2012.

Tuckerman Ravine has Moderate and Low avalanche danger. The Sluice, Lip, and Center Bowl have Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible. All other forecast areas in Tuckerman have Low avalanche danger. Natural and human triggered avalanches are unlikely. Huntington Ravine is under a General Advisory. You will need to do your own snow stability assessments when using avalanche terrain in Huntington. A danger of falling ice exists, and will persist until it all comes down.

Today has the potential to be another great day for skiing, riding, or hiking, but this mountain presents a wide variety of hazards that you’ll want to be aware of. Rapidly warming temperatures today will exacerbate the usual springtime hazards, predominantly icefall and crevasses. Additionally, there are some avalanche concerns that you need to know about if you plan to be in avalanche terrain, which includes the floor of Tuckerman Ravine and the Lunch Rocks area. Yesterday, skier and snowboarder traffic tested and cut up the slabs in Hillman’s, Left Gully, and the Chute areas. Thanks to them, I feel better about dropping the rating in these locations to Low for today, but if you venture into areas of virgin snow you may find a slab with enough energy to create an avalanche. In the areas posted at Moderate, the concern is primarily related to the rapid warming today. Heat on the snowpack can lead to both stability and instability, depending on how it is applied and the timing. In this case, I’m thinking we’ll have enough warming to break down some of the strength that has developed in the upper layers of the snow, but not enough to fully stabilize the deeper layers. As the upper layer strength is eroded away, your impact as a skier or climber can more easily penetrate and reach those buried weak layers. This will be more problematic in the areas that get the most direct sunlight and have not had significant traffic, namely the Sluice, Lip, and Center Bowl.

Icefall has been occurring from the Headwall and Sluice areas. It is important that you recognize this hazard and take steps to avoid being underneath ice when it falls. Icefall hazard will increase this week as temperatures skyrocket. The greatest icefall hazard exists from the Center Headwall and the Sluice ice above Lunch Rocks. Icefall can happen fast and can be enormous, shattering ice in multiple directions. Lunch Rocks is not be considered a safe place to be. Of course, you should always be looking uphill and thinking about what might fall from above…ice, avalanches, dropped snowboards, people without crampons, etc. can quickly turn a great day into a disaster.

The Center Bowl and Lip area have numerous deep crevasses from earlier warm weather that is now hidden by new snow. Currently, you cannot see where these are, so you will not be able to assess the hazard safely without roping up and probing ahead. Because the consequences of falling into one of these crevasses are severe we recommend avoiding this area entirely. There are some smaller crevasses outside of the Lip and Center Bowl area, and underneath the Sluice ice is another area where we historically have seen very dangerous undermined snow and crevasse hazard.

 Hikers should not plan to use the Tuckerman Ravine Trail to climb to or descend from the alpine zone and the summit of Mt. Washington. From Pinkham, Lion Head and Boott Spur are much better options. The John Sherburne Ski Trail is currently open about halfway down. We expect the skiable terrain to be shortened by tomorrow.

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 Mount Washington Volunteer Ski Patrol, and the AMC at Pinkham Notch or Hermit Lake.  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

PDF version 2012-04-15

Avalanche Advisory for Saturday, 4-14-2012

This advisory expires at midnight, Saturday 4-14-2012

Tuckerman Ravine has MODERATE avalanche danger.  Natural avalanches are unlikely and human triggered avalanches are possible.  Heightened avalanche conditions exist on specific terrain features.  Evaluate snow and terrain carefully to identify features of concern.  The Lower Snowfields and Right Gully have Low avalanche danger. The Lobster Claw and the Little Headwall are not posted due to lack of snow.  Huntington Ravine is under a General Advisory. You will need to do your own snow stability assessments when using avalanche terrain in Huntington. A danger of falling ice exists, and will persist until it all comes down

 Let’s get right into today’s hazards for Tuckerman Ravine.

AVALANCHES: We spent the day in the field yesterday and our predictions were right on the money.  Cold slabs harboring instabilities exist in many of the upper elevations of the Ravine.  The areas we are most concerned about exist from the Left Center Headwall through the upper Chute to the south.  Other isolated cold instabilities can be found in the Lip region and more prominently in the Chute variations, the top of Left Gully and the top of Hillman’s.  The weak layer in most areas is a layer of graupel (little snow ball bearings) of varying thicknesses.  This was the failure layer in several Extended Column Tests with results in the single numbers indicating areas of unstable snow.  Cold snow instabilities will be the primary avalanche issue this morning, but as the day wears on intense warming should affect all aspects as winds slacken and summit temperatures move into the thirties F.  Our local valleys will see temperatures into the 70’s F.  What this translates into is some wet slab issues later today.  South facing slopes will get the warmest today, but have already been through some heating over the last couple of days.  Therefore they should be able to handle today’s warming a little better than other aspects that still possess cold slabs.  As solar gain increases there will likely be a period trending towards increasing stability, however eventually may turn back in the other direction as the sun bakes out snow cohesiveness.  I believe “Moderate” addresses the issues today better than Low or Considerable, but if slabs heat up enough and thinner portions lose strength the danger may be on the upper end of the Moderate rating.  Although natural slab avalanches are unlikely I wouldn’t say they’re impossible, particularly in the steepest of terrain.  I would expect sluffing snow to occur, especially by skiers late in the day.  If this happens from up high, the entrained snow could have enough impact to trigger a lower slab.  The last avalanche concern relates to the number of triggers that may be out in the terrain today considering it’s a sunny Saturday.  Therefore expect numerous potential weaknesses to be tested by skiers, riders, and mountaineers.  Be very cautious about what slopes you are under with instabilities and people above.  Realize avalanches can run down the length of the Ravine floor so sledding, sliding, hanging out, etc. under these avalanche paths puts you at risk of burial.

FALLING ICE:  We saw a number of ice chunks fall yesterday from the Headwall.  This should increase today with the heat hitting the highest point since last month’s record heat wave.  The greatest icefall hazard exists from the Center Headwall and the Sluice ice above Lunch Rocks.  Both these areas pummel Lunch Rocks with ice, so sitting there should be avoided.  Many injuries and some fatalities have occurred in this area.  Icefall is one of the most difficult hazards to predict and time, but realize it can happen fast and can be enormous, shattering ice in multiple directions.  Sitting and hanging out down to the left on the opposite side of the Ravine, out of avalanche paths, is a safer option to avoid ice.

CREVASSES AND HOLES:  The Center Bowl and Lip area have numerous deep crevasses from earlier warm weather that is now being hidden by new snow.  You will not be able to assess this hazard safely because of their hidden nature. Many of these deep slots possess weak snow bridges that can collapse under your weight.   Because the consequences of falling into one of these crevasses are severe we recommend avoiding this area entirely.  Hikers should not use Tuckerman Ravine to access the alpine zone and the summit of Mt. Washington. Also, you should not descend down from these areas into the Ravine.   

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 Mount Washington Volunteer Ski Patrol, and the AMC at Pinkham Notch or Hermit Lake.  A new advisory will be issued tomorrow.

Christopher Joosen, Snow Ranger
USDA Forest Service, White Mountain National Forest

2012-04-14 Print Version

Avalanche Advisory for Friday, 4-13-2012

This advisory expires at midnight, 4-13-2012

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

Finally a sunny day on the mountain!  Today marks the first day without precipitation for the month of April. The summit has received 33” of snow since the 1st,  of which 24” fell since last weekend.  Once again the mountain is deciding when it’s over and when winter is still her fancy.  Settlement of unstable slabs has been slow, but a trend towards stability has been occurring due to the diurnal warming and cooling.  As on Wednesday, yesterday the Hermit Lake mercury climbed into the high 30’sF (3C) just after 3pm before falling below freezing again overnight.  This has allowed a steady consolidation of slabs in Tuckerman, keeping the snow up on steep slopes with very little avalanche activity since the initial heavy accumulation on Monday.  Above Hermit Lake, up to the Ravine rim, temperatures did get above freezing, but barely as you get to the upper reaches of avalanche terrain.  Because of this expect more stable conditions down low than up in the traditional avalanche start zones, especially those less affected by the sun.  Some examples of colder slab concerns are up high in the Chute, Left Headwall, as well small buttress shoulders in terrain that point to the north and are shadowed later in the day. 

A number of aspects, particularly south facing slopes, are showing evidence of intense rollerballing or snowballing from periods of sun yesterday with low winds.  I would expect this to intensify as we will likely see the warmest, sunniest day all week today.  Strong lee S and SE facing slopes sheltered by the NW wind in the direct sun will get the warmest today, which does bring some concern of instability issues created by rapid warming.  The last 2 days of warming are comforting so southern slopes will be able to handle some warming, but be wary of intense long-duration baking today.  If your assessments determine you feel comfortable on these slopes I would consider getting on them in the first half of the day and giving them some room as heating intensifies. We are already exceeding the forecasted wind speeds today with current gusts hitting the 50mph mark from the NW.  This will help keep a number of slopes cool, likely hanging on to cold slabs that are exposed to winds from the northwesterly direction such as high in Left gully, and the Chute. 

To summarize, we have two very different avalanche issues today.  We will be in the field assessing and posting any information we garner to the Weekend Update this afternoon.  First, we have cold slabs up high and on some mid-elevation slopes that aren’t directly impacted by direct sun influence that will need your caution and evaluation.  Stability will change as you travel due to the thickness of slabs, the differing age of surface slabs, the cooling effect of wind exposure, etc.  Therefore anticipate variable problems and potential weaknesses reactive to you as the trigger.  And second, we have the potential for excessive warming causing some wet slab issues on SE and S slopes like the Sluice and Lip area.  Areas that are reasonable options to be in are the lower half of Hillman’s and Left Gully as long as there are not human triggers above you in more unstable snow.  This can often be difficult to see and determine.

Falling ice hazard will begin increasing today and through the weekend.  The Center Bowl and Lip area have numerous deep crevasses from earlier warm weather that is now being hidden by new snow. Expect all of these to be covered visibly by new snow, which makes for weak bridges that can collapse under your weight. You will not be able to assess this hazard safely because of their hidden nature and the consequences of falling into one of these crevasses are severe.  We recommend avoiding this area entirely. Hikers should not use Tuckerman Ravine to access the alpine zone and the summit of Mt. Washington. Also, you should not descend down from these areas into the Ravine.   

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 Mount Washington Volunteer Ski Patrol, and the AMC at Pinkham Notch or Hermit Lake.  A new advisory will be issued tomorrow.

Christopher Joosen, Snow Ranger
USDA Forest Service, White Mountain National Forest

2012-04-13 Print Version

Avalanche Advisory for Thursday, 4-12-2012

This advisory expires at midnight, Thursday 4-12-2012

Tuckerman Ravine has MODERATE avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible.  Heightened avalanche conditions exist on specific terrain features.  Evaluate snow and terrain carefully to identify features of concern.  The Lobster Claw and the Little Headwall are not posted due to lack of snow.  Huntington Ravine is under a General Advisory. You will need to do your own snow stability assessments when using avalanche terrain in Huntington. A danger of falling ice exists, and will persist until it all comes down.

Some brief clearing yesterday morning with some flat light views into avalanche terrain was bullied out by a dropping cloud ceiling and the return of snow showers.   The summit recorded another 2” (5cm) of snow giving the higher elevations 2 feet of accumulation since the weekend.  The past several inches have fallen with low wind speeds, which are forecasted to pick up today.  Velocities should increase up to 40mph from the current of 17mph and shift from the N to the NW.  This may begin transporting some new snow sitting above treeline from the past 36 hours down into avalanche terrain particularly the up reaches of the Sluice and the Lip.  Cross loading of east facing aspects is also possible but to a lesser degree.  Light snow showers this morning will continue until some clearing begins this afternoon giving us perhaps an additional inch to weigh in the equation. Rain is also not out of the question.

Depending on exactly how today’s weather plays out we are teeter tottering between Moderate and Considerable avalanche danger particularly SE and E facing slopes, namely the Sluice, Lip, and Center Bowl.   First, the reasons why I believe we won’t quite make it to a Considerable rating today, but will be on the upper end of Moderate for the aforementioned locations.  The vast majority of snow this week available for transport from the higher elevations down into the avalanche terrain has already happened.  High winds gusting to 80mph occurred on Monday tapering to gusts into the mid 50’s through Tuesday morning.  An occasional spike later that evening into the upper 40’s has since mellowed to 30mph or lower.  Generally, the only snow left available for today’s maximum winds is about 2-3” which has bonded and settled over the past 36 hours due to rising temperatures.  Bigelow Lawn and the Alpine Garden, two areas that typically load snow into Tuckerman, were very close to the freezing mark and sensors show they briefly exceeded the critical 32 degree point.  Below this elevation exists all of our avalanche terrain which in turn also went above freezing with some paths like lower Hillman’s hitting about 36F.  Dropping temperatures overnight has refrozen free-water strengthening the upper snowpack, especially slopes at lower elevations.  This has helped the stabilizing trend, but has had limited effect in some of our deeper slabs in the upper reaches of Tuckerman’s avalanche terrain. However, existing slabs no longer deserve a definition that reads that natural avalanches are possible and human triggered avalanches are likely.  Saying this, it’s important to recognize that as we drop to “Moderate” our current widespread deep slabs should be respected and although the likelihood of initiating a failure causing an avalanche is lower than yesterday, it would still be close in size-Large. The possibility of a human triggered avalanche is greater high in the Ravine’s colder snow.  Slopes near the Headwall elevation from the Lip over to the Chute have the highest potential for weak slabs. 

There are several issues to watch that would push us over the fence from the upper end of “Moderate” to “Considerable” todayIf snow accumulations exceed an inch today, winds shift to the NW earlier than expected, and maximum winds exceed 40mph think about an increasing avalanche danger.  The most threatening factor to watch that can increase the avalanche danger most rapidly today is the potential for rain.  Although the higher elevations are expecting some snow our avalanche terrain to the 5000ft level could see some liquid today.  Water equivalents for Gorham and North Conway are showing up to 0.15” on the upper end.  Some of that moisture is currently being squeezed out as snow above 2000ft.  If rain does occur it should be light, but through some orographic effect and clouds interacting with the terrain the final amounts between snow and rain could exceed the valley expectations. I would be thinking more about the potential for small natural avalanches possibly stepping down into something larger if additional snow loading and particularly rain occur today.  Watch for rain and loading evidence as your day unfolds and change plans accordingly to lower your risk.     

As if avalanche danger wasn’t enough to make you stay out of the area, you need to know that the Center Bowl and Lip area have numerous deep crevasses. Expect all of these to be covered visibly by new snow, which makes for weak bridges that can collapse under your weight. You will not be able to assess this hazard safely because of their hidden nature and the consequences of falling into one of these crevasses are severe.  We recommend avoiding this area entirely. Hikers should not use Tuckerman Ravine to access the alpine zone and the summit of Mt. Washington. Also, you should not descend down from these areas into the Ravine.     

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.  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

2012-04-12 Print Version

Avalanche Advisory for Wednesday, 4-11-2012

This advisory expires at midnight, Wednesday 4-11-2012

Tuckerman Ravine has CONSIDERABLE and MODERATE avalanche danger. The Sluice, Lip, Center Bowl, Chute, and Left Gully have Considerable avalanche danger.  Natural avalanches are possible and human triggered avalanches are likely. Right Gully, Hillman’s Highway, and the Lower Snowfields have Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible.  Lobster Claw and the Little Headwall are not posted due to an overall lack of snow in these areas. Huntington Ravine is under a General Advisory. You will need to do your own snow stability assessments when using avalanche terrain in Huntington. A danger of falling ice exists, and will persist until it all comes down.

The summit recorded another 3.1” (7.5cm) of snow giving the higher mountain about 22” over the past 3 days.  Another 1-3” of snowfall is anticipated through the forecast period with reasonably light winds from the N and NNE at 10-25mph (16-40kph).  This may add a bit more light snow slab development near the ridgeline of several forecast areas; however most of the instability problems we face today have already been developed by loading on Monday and Tuesday.  This past loading occurred from a general W wind blowing between 35 and 75 mph over the last 72 hours. 

With the 5-scale danger ratings it is important to remember to put aside what you believe the key word (Extreme, High, Considerable, Moderate, and Low) means to you, but use it to link to the definition.  The “Considerable” rating means that naturally triggered avalanches are possible and human triggered avalanches are likely.  And “Moderate” states natural avalanches are unlikely and human triggered avalanches are possible.  These words reflect the likelihood of slope failure and not the size and destructive force.  I say this because unstable slabs associated with mid to late spring skiing are usually smaller than our current situation.  Realize we are going through a mid-winter avalanche/instability scenario so if slope failure occurs with our current slabs expect a number of them to run full path (aka- Big!).   Under the “Considerable” rating the size and distribution statement is flexible to address numerous situations depending on the actual snowpack weaknesses.  It reads, “small avalanches in many areas; or large avalanches in specific areas; or very large avalanches in isolated areas.”  “Large avalanches in specific areas” covers our current situation fairly well from the Lip over to the Chute.  Be conservative and give the slopes some time to stabilize.  A little patience would be a prudent choice.  Warmer air over the next couple of days may increase our concerns briefly, but will ultimately help consolidate the snowpack.

As if avalanche danger wasn’t enough to make you stay out of the area, you need to know that the Center Bowl and Lip area have numerous deep crevasses. Expect all of these to be covered entirely by new snow, which makes for weak bridges that can collapse under your weight. You will not be able to assess this hazard safely and the consequences of falling into one of these crevasses are severe, so we recommend avoiding this area entirely. Hikers should not use Tuckerman Ravine to access the alpine zone and the summit of Mt. Washington. Also you should not descend down from these areas into the Ravine.

The Lion Head Trail does travel through known avalanche paths so having avalanche assessment skills will be important.  As with many trails that run through avalanche terrain in the Presidentials and the White Mountains that aren’t covered by avalanche forecasts you should be prepared to do stability tests and make your own evaluation.   

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 Mount Washington Volunteer Ski Patrol, and the AMC at Pinkham Notch or Hermit Lake.  A new advisory will be issued tomorrow.

Christopher Joosen, Snow Ranger
USDA Forest Service, White Mountain National Forest

2012-04-11 Print Version

Avalanche Advisory for Tuesday, 4-10-2012

This advisory expires at 12:00 midnight, April 10, 2012.

All forecasted areas of Tuckerman Ravine have Considerable avalanche danger.  Natural avalanches are possible and human triggered avalanches are likely. Lobster Claw and the Little Headwall are not posted due to an overall lack of snow in these areas. Huntington Ravine is under a General Advisory. You will need to do your own snow stability assessments when using avalanche terrain in Huntington. A danger of falling ice exists, and will persist until it all comes down.

This late in the season, avalanches might not be on your mind too frequently, so let’s review a critical component of an avalanche forecast, the danger rating. Today’s rating is Considerable, which means that naturally triggered avalanches are possible and human triggered avalanches are likely. For the backcountry traveler, this means that you don’t need to be high up on a steep slope to be at risk of getting hit with an avalanche. All you need to do is be in the potential runout zone and Mother Nature will take care of the rest. My hackles go up when I hear someone tell me they’re “just going up to check it out” or “not going very high.” Another part of the definition for Considerable danger relates to travel advice. It states, “Careful snowpack evaluation, cautious route-finding, and conservative decision making essential.” This is good advice for a day like today, when Mt. Washington remains in the grips of a multi-day winter storm. Currently, visibility is incredibly limited in the Bowl. Be honest with yourself, and if you don’t have the knowledge and experience to know exactly where you are in relation to avalanche paths, and to make these assessments and route choices, it would be a good idea to play it safe and avoid avalanche terrain.

Ok, I’m off my soapbox now, so on to the details. Over the last couple days, the upper parts of the mountain have received plentiful snow. Our storm board at Hermit Lake had 37cm (14.5”) on it as of 6:30 this morning. The summit has recorded more than that, coming in just under 48cm (19”) since snow began on Sunday afternoon. Additional snowfall will come today, though totals won’t be as great as they were yesterday. Much of the recent snow fell during strong winds that meandered in the N to W range of the compass rose. Lately they’ve been from the W and are forecasted to be in the 25-40mph (40-65kph) range, which will load and cross load snow into all forecast areas. Those areas in the strongest lee, such as the Sluice, Lip, Center Bowl, and Chute will pose the greatest threat. Right Gully and the Lower Snowfields have bed surfaces that are much less developed, so therefore will be in the lower end of the Considerable range.

As if avalanche danger wasn’t enough to make you stay out of the area, you need to know that the Center Bowl and Lip area have numerous deep crevasses. Expect all of these to be covered entirely by new snow, which makes for weak bridges that can collapse under your weight. You will not be able to assess this hazard safely and the consequences of falling into one of these crevasses are severe, so we recommend avoiding this area entirely. Hikers should not use Tuckerman Ravine to access the alpine zone and the summit of Mt. Washington. Also you should not descend down from these areas into the Ravine.

The Lion Head Trail does travel through known avalanche paths. We have not yet been able to assess these slide paths, so I won’t guarantee there is no avalanche hazard there today. The location with the greatest hazard here would be the snowfield traverse just as you arrive at treeline. I recommend choosing a different route, or traveling with the appropriate avalanche equipment and practicing safe travel techniques for avalanche terrain.

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.
  • 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

2012-04-10 Print Friendly

Avalanche Advisory for Monday, April 9, 2012

This advisory expires at 12:00 midnight, April 9 2012

Tuckerman Ravine has Considerable and Moderate avalanche danger today.  The Sluice, Lip, Center Bowl, and Chute have Considerable avalanche danger. Natural avalanches are possible and human triggered avalanches are likely. Right Gully, Left Gully, and Hillman’s Highway have Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible. Huntington Ravine is under a General Advisory. You will need to do your own snow stability assessments when using avalanche terrain in Huntington. A danger of falling ice exists, and will persist until it all comes down.

Three weeks ago, I certainly didn’t see this coming. April often has good winter storms, so we shouldn’t be surprised to come to the day where we’re thinking about the potential for natural avalanche activity. Prior to yesterday, there had been several smaller snow events that laid down a blanket of new snow in strong lee areas of Tuckerman, such as the mid-elevations in the Sluice, Lip, and Center Bowl, as well as in pockets of new snow in most other areas. On Sunday, snowfall began across the higher terrain. This continued through the night, all through Monday, and is still ongoing today. Early in the event there was a period of very light density snow, followed by graupel, followed by increasing density and stronger winds. These winds have been from the N, NNW, NW, and WNW throughout much of this time, though recently they’ve shifted further and are now coming from the W. Snowfall in the last 24 hours was 6.2” at the summit and 5.1” at Hermit Lake. Over the past 48 hours the summit has received about 9” total new snow.

If you’ve spent time studying avalanche behavior on Mt. Washington, you’ll already know where I’m going with this info. Today’s forecast calls for strong W winds in the 50-70mph range and additional snow accumulating potentially to another 6” in favored locations such as Tuckerman. These variables all lead me to believe that natural avalanche activity will be possible in several areas today. Areas posted at Moderate will be increasing in avalanche danger as well. If new snow totals are near the upper end of the forecasted range, the avalanche danger in these areas may exceed the current rating. If you’re traveling into steep terrain today, you’d better bring your A-game and knock the rust off your avalanche skills. Low visibility makes traveling safely in avalanche terrain much more difficult to do. So while it’s critical that you bring avalanche safety gear (i.e. at minimum, a beacon, shovel, and probe), really you need to bring good judgment and the ability to choose your route wisely. It’s all-too-common to see people flock to the area with the lowest danger rating. Doing so today without considering the snow stability issues would not be a prudent move.

As if avalanche danger wasn’t enough to make you stay out of the area, you need to know that the Center Bowl and Lip area have numerous deep crevasses. Expect all of these to be covered entirely by new snow, which makes for weak bridges that can collapse under your weight. You will not be able to assess this hazard safely and the consequences of falling into one of these crevasses are severe, so we recommend avoiding this area entirely. Hikers should not use Tuckerman Ravine to access the alpine zone and the summit of Mt. Washington. Also you should not descend down from these areas into the Ravine. The Lion Head Trail is a much safer option, but you should still be prepared for this trail with an ice axe, crampons, and good winter equipment.

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, the caretaker at Hermit Lake Shelters.
  • 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

2012-04-09 Print Friendly

Avalanche Advisory for Sunday, 4-08-2012

This advisory expires at midnight, Sunday 4-08-2012

Tuckerman Ravine has Low avalanche danger. Natural and human triggered avalanches are unlikely except in isolated terrain features. These pockets do exist.  Huntington Ravine is under a General Advisory. You will need to do your own snow stability assessments when using avalanche terrain in Huntington. A danger of falling ice exists, and will persist until it all comes down.

Weather and its effect on Mount Washington continue to impress me.  Only 3 weeks ago we were enduring an unprecedented heat wave melting the Ravine before our eyes.  We knew this could all change again, but the season’s longevity wasn’t looking pretty.  As the heat was ushered out winter returned and really hasn’t left!  Tuckerman’s coverage has been close to a state of suspended animation, changing ever so slowly.  Big ice has redeveloped in the Sluice and Headwall joining older ice from the winter, crevasses are slowly growing and undermining is present although fairly stagnant.  Then, just to be difficult, Mother Nature has hidden these by steady shots of new snow causing some avalanche concerns.  Overnight the summit received 2.5” (6cm) of light 3.6% density snow on N/NW winds from 35 to 55mph (56-88kph).  This adds up to 10.5” over the past week which has been filling in the nooks and crannies and giving us some snow stability concerns.  Old surface is still present in most of the Ravine, however isolated low density pockets of slab could be triggered by a human traveler particularly locations high and tight under terrain features on the steepest slopes between the Headwall and the Sluice.  An additional inch today and possibly another 4” tomorrow with W winds gusting over 70mph will increase the avalanche danger.  Until then today’s bulls-eye points in addition to avalanche concerns are:

  1. FOG WILL LIMIT YOUR HAZARD ASSESSMENT.  Fog forecasted today will make assessing all the hazards you face very difficult, this dramatically increases your risk.  Many seasoned mountaineers consider fog a “no-go/red light” day.
  2. The northern side of the Ravine, primarily the Lip area, has the vast majority of large crevasses.  These have been obscured by recent snowfalls, making them impossible to safely assess, but it’s entirely possible that you would fall into one if you were to ski, hike, or slide over it.  Many of these are very deep with severe consequences. Travel from the Ravine floor to the ridgeline on the climber’s right side of the Ravine from the Center Bowl to the Sluice, including the “Lip” area IS NOT RECOMMENDED AND SHOULD BE AVOIDED.  
  3. Hikers should not use Tuckerman Ravine to access the Alpine Zone and the Summit of Mount Washington.  Equally, they should not descend down from these areas into the Ravine.  The Lion Head trail is a much safer option.  Of course be prepared with appropriate clothing, an ice ax, and crampons.  
  4. The southern side of the Ravine, including the Chute and Left Gully has far less “objective hazards”, such as icefall, undermining, crevasses, and avalanches than on the northern side. These are dangers you can’t control, but you can avoid them by choosing where you travel. Your overall risk is far lower in these southern locales, or left side of the Ravine.  As in all locations think about long sliding falls due to hard surface conditions.

Whether you’re on skis or on foot, falling in steep terrain is not an option. An ice axe, crampons, and real mountaineering boots are absolutely critical for climbing safely in these conditions. Simply having these tools isn’t enough. You need to know how to use them, and understand the limits of their effectiveness in steep icy terrain. The hard old surface makes belayed climbing on the steeper slopes a wise technique. Also think about what is below you—rocks, chunks of ice, crevasses, etc—these greatly increase the consequences of a sliding fall.

Again, crevasses, undermined snow, and waterfall holes are a serious threat. Currently the area from the Sluice to the Center Bowl is littered with crevasses. New snow makes them nearly impossible to see. The hazards presented by the crevasses are not to be taken lightly; consider it “no-fall” terrain.  Because of the extent of crevasses, the severity of the consequences, and the inability to assess the hazard, the greater Lip area, which includes a section of the summer hiking trail, should be avoided entirely.

Falling ice can also happen, even on cold days. A couple times over the past week we have watched ice fall into Lunch Rocks while air temperatures were below freezing. Your best defense against falling ice is to avoid being anywhere near the possible runouts. The locations at greatest risk for this hazard are the Sluice, Lunch Rocks, the Lip, and the Center Bowl. Other areas aren’t immune though, so always be aware of what’s above you. And remember, ice doesn’t always fall in a straight path downslope.

The Sherburne Ski Trail is still open about 1/3 of the way down and is currently a mix of lots of water ice, exposed rocks, with a little bit of new snow hiding these problems.  Cross over to the hiking trail at the rope.

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 Mount Washington Volunteer Ski Patrol, and the AMC at Pinkham Notch or Hermit Lake.  A new advisory will be issued tomorrow.

Christopher Joosen, Snow Ranger
USDA Forest Service, White Mountain National Forest

2012-04-08 Print Version

Avalanche Advisory for Saturday, 4-7-2012

This advisory expires at 12:00 midnight, April 7, 2012.

Tuckerman Ravine has Low avalanche danger. Natural and human triggered avalanches are unlikely except in isolated terrain features. Huntington Ravine is under a General Advisory. You will need to do your own snow stability assessments when using avalanche terrain in Huntington. A danger of falling ice exists, and will persist until it all comes down.

This morning at dawn Tuckerman was in full sunshine, bright, clear, and cold. However, as the morning has progressed, the cloud deck has started to lower in a prelude of what’s to come today. The lowering clouds will continue and light snow showers are expected for the evening and night. Conditions today will be almost identical to yesterday. If you are thinking about traveling into steep terrain, be prepared for icy conditions. Don’t expect to follow a well-established boot pack; you should be expecting to put your cramponing skills to use instead. It’ll be a great day to practice conservative decision making, but not a good day for pushing the limits of your climbing ability and tolerance for risk.

Several inches of new snow have dotted the ravine with patches of white. In the deepest locations, such as the Sluice and Lip area, you should be thinking of these as potential avalanche producers and assessing their stability. But, before you decide to go to one of these two areas, have every person in your group read carefully through the rest of this advisory before making a final decision. From a skier/snowboarder perspective, arriving in the Bowl you will be attracted to the creamy white appearance of the snow in the Lip and Sluice. I’ll admit, it looks far better than the icy moguls of Left Gully or the scratchy chunder of the Chute. Herein lies the problem. These areas have far more objective hazard than the other areas. That is to say, the hazards have little to do with your skiing or climbing ability. In the current conditions situation, you are not fully in control of your own risk in these areas. In the Sluice, you will be underneath several hundred tons of ice that is just waiting for the right moment to crash down. In the Lip, numerous crevasses have been obscured by recent snowfalls, making them impossible to safely assess, but it’s entirely possible that you would fall into one if you were to ski, hike, or slide over it.

Whether you’re on skis or on foot, falling in steep terrain is not an option. An ice axe, crampons, and real mountaineering boots are absolutely critical for climbing safely in these conditions. Simply having these tools isn’t enough. You need to know how to use them, and understand the limits of their effectiveness in steep icy terrain. The hard old surface makes belayed climbing on the steeper slopes a wise technique. Also think about what is below you—rocks, chunks of ice, crevasses, etc—these  greatly increase the consequences of a sliding fall.

Crevasses, undermined snow, and waterfall holes are a serious threat. Currently the area from the Sluice to the Center Bowl is littered with crevasses. A thin coating of newer snow makes them nearly impossible to see. The hazards presented by the crevasses are not to be taken lightly; it is truly “no-fall” terrain. Taking into account the extent of crevasses, the severity of the consequences, and the inability to assess the hazard, the greater Lip area, which includes a section of the summer hiking trail, should be avoided entirely.

Falling ice can also happen, even on cold days such as this. A couple times over the past week we have watched ice fall into Lunch Rocks while air temperatures were below freezing. Your best defense against falling ice is to avoid being anywhere near the possible runouts. The locations at greatest risk for this hazard are the Sluice, Lunch Rocks, the Lip, and the Center Bowl. Other areas aren’t immune though, so always be aware of what’s above you. And remember, ice doesn’t always fall in a straight path downslope.

The Sherburne Ski Trail is open about 1/3 of the way down is currently a mix of lots of water ice, exposed rocks, and my personal favorite, “packed powder”. It might make your descent a little easier than walking, but I personally wouldn’t recommend coming up just to ski the Sherby. Cross over to the hiking trail at the rope. 

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, the caretaker at Hermit Lake Shelters.
  • 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

2012-04-07 Printable #2

 

Avalanche Advisory for Friday, 4-6-2012

This Advisory expires at 12:00 midnight, April 6, 2012

Tuckerman Ravine has Low avalanche danger. Natural and human triggered avalanches are unlikely except in isolated terrain features. Huntington Ravine is under a General Advisory. You will need to do your own snow stability assessments when using avalanche terrain in Huntington. A danger of falling ice exists, and will persist until it all comes down.

When is the weather ever going to seem normal again? How about today? This is exactly the kind of weather I’ve come to expect from early April. It’s probably going to be a pleasant day down in the valley, but up on Mt. Washington it’s cold and winter-like. Over the past 48 hours, the summit has recorded 3.1” (8cm) of new snow. During this time winds have been consistently from the NW ranging from 40 to the low 80mph range (65-130kph). This is keeping us on guard for “isolated pockets” of unstable snow. Winds have loaded snow into some lee areas but had a hard time depositing anything onto some of the other exposed crust around the mountain. One thing you can count on with the current snowpack is the excellent stability of the old surface. Unfortunately, this is the very same surface that most people avoid like the plague, except for ice climbers. Skiers and snowboarders should take the time to assess each individual area of new snow, since the depth, consistency, and stability of each might be very different from others that are in close proximity. Weather today will be a battle between high pressure and a deep trough, perhaps allowing for some breaks in the clouds but you should be prepared to deal with very limited visibility. The existing hazards can be incredibly difficult to assess, both due to the fog and to the accumulations of new snow hiding these features.

Crevasses, undermined snow, and waterfall holes are a serious threat. Currently the area from the Sluice to the Center Bowl is littered with crevasses. Most of these are covered with a thin coating of newer snow, which makes them nearly impossible to safely assess their exact location and depth. The hazards presented by the crevasses are not to be taken lightly; it is truly “no-fall” terrain. Taking into account the extent of crevasses, the severity of the consequences, and the inability to assess the hazard, the greater Lip area, which includes a section of the summer hiking trail, should be avoided entirely.

Surfaces will be icy and hard below the new snow, so long sliding falls continue to be another significant hazard. The slick surface will allow for rapid acceleration down slope, potentially sending you into numerous obstacles below you. An ice axe, crampons, and real mountaineering boots are absolutely critical for climbing in these conditions safely. The hard surface beneath the new snow makes belayed climbing on the steeper slopes a wise technique.  Because the current surface conditions have made most steep slopes “no fall” territory, the ability to use technical mountaineering skills and equipment effectively is imperative.

Falling ice can happen, even on cold days such as this. A couple times over the past week we have watched ice fall into Lunch Rocks while air temperatures were below freezing. There is a lot of new ice from the cold weather over the past couple weeks. Your best defense against falling ice is to avoid being anywhere near the possible runouts. The locations at greatest risk for this hazard are the Sluice, Lunch Rocks, the Lip, and the Center Bowl. Other areas aren’t immune though, so always be aware of what’s above you.

The Harvard Cabin is now closed for the season. The only camping permitted in the Cutler River Drainage is at Hermit Lake Shelters. The Sherburne Ski Trail is open about 1/3 of the way down is currently a mix of water ice, exposed rocks, and my personal favorite, “packed powder”. Cross over to the hiking trail at the rope.

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, the caretaker at Hermit Lake Shelters.
  • 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

2012-04-06 Print Friendly

Avalanche Advisory for Thursday, 4-05-2012

This advisory expires at midnight, Thursday 4-05-2012

Tuckerman Ravine has Low avalanche danger. Natural and human triggered avalanches are unlikely except in isolated terrain features. The Lobster Claw, the Lower Snowfields, and the Little Headwall are not posted due to lack of snow. Huntington Ravine is under a General Advisory. You will need to do your own snow stability assessments when using avalanche terrain in Huntington. A danger of falling ice exists, and will persist until it all comes down.

Coming in right on schedule, new snow started falling very late Wednesday afternoon giving the mountain 1.3″ by around midnight.  Since then, a bit more has fallen riding in on a strong NW wind gusting to hurricane force (77-80mph/120-128kph).  A slight chance of snow showers will continue today with increasing fog and continued windy conditions.  Summit temperatures will continue to stay quite wintry for the week ahead, moving from the teens today down into the lower single numbers overnight before rebounding slightly again tomorrow.  An ever-so-slight increase over the weekend will help the comfort level a little, but anticipate the summit to only reach the 20F degree mark.  Isolated areas of newly deposited windslab from the past 72 hours of light snow are slow to consolidate with the cold air in place and high winds.  Remember to constantly re-evaluate each new area of cold slab you enter and not presume it was as stable as the last one you traveled through.  This is particularly true on steeper or in more protected terrain features from W and NW winds.   Additionally, be thinking about your changing fall line and runout. A small slab that knocks you off your feet may not bury you, but the consequences of a fall can be severe.  One of the current problems that will greatly exacerbate the hazards in the Ravine is the potential for dropping clouds and fog.  Historically this has caused a number of accidents because it is very difficult to assess hazards if you can’t see them.  This is particularly true trying to ski or ride in areas with crevasses or deal with falling ice moving at 50mph down slope when you can’t see it coming.  For many seasoned mountain travelers fog is a “red light-no go” indicator.

Crevasses, undermined snow, and waterfall holes continue to be a serious threat. Currently the area from the Sluice to the Center Bowl is littered with crevasses. Most of these are covered with a thin coating of newer snow, which makes them nearly impossible to safely assess their exact location, size and depth. The hazards presented by the crevasses are not to be taken lightly; it is truly “no-fall” terrain. Taking into account the extent of crevasses, the severity of the consequences, and the inability to assess the hazard, the greater LIP area, which includes a section of the summer hiking trail should be avoided entirely.  This is also true for the heavily crevassed areas in the northern portions of the Center Bowl underneath the headwall ice, Lip and areas towards the Sluice all the way down to the Ravine floor.  Foggy conditions will make all these problems worse.

Surfaces will be icy and hard below the new snow, so long sliding falls continue to be another significant threat. The slick surface will allow for rapid acceleration down slope, potentially sending you into numerous obstacles below you. An ice axe, full 10-12 point crampons, and real mountaineering boots are absolutely critical for climbing in these conditions safely. The hard surface beneath the new snow makes roped climbing with anchors on the steeper slopes a wise technique in certain situations. Because the current surface conditions have made most steep slopes “no fall” territory, the ability to use technical mountaineering skills and equipment effectively is imperative.

Even though temperatures this week will not be very warm, falling ice is a possibility. This was exemplified yesterday as ice fell out of the Sluice and crashed through Lunch Rocks (aka “Icefall Rocks”) There is a lot of recently formed ice from the cold weather over the past couple weeks. Your best defense against falling ice is to avoid being anywhere near the possible runouts. The locations at greatest risk for this hazard are the Sluice, Lunch Rocks, the Lip, and the Center Bowl. Other areas aren’t immune though, so always be aware of what’s above you. The Harvard Cabin is now closed for the season. The only camping permitted on the eastern side of Mount Washington is at Hermit Lake Shelters. The Sherburne Ski Trail is open about 1/3 of the way down; please cross over to the hiking trail at the rope.

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, the caretaker at Hermit Lake Shelters. 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

4-05-2012 Print Friendly

Avalanche Advisory for Wednesday 4-04-2012

This advisory expires at Midnight, Wednesday 4-04-2012

Tuckerman Ravine has Low avalanche danger. Natural and human triggered avalanches are unlikely except in isolated terrain features. The Lobster Claw, the Lower Snowfields, and the Little Headwall are not posted due to lack of snow. Huntington Ravine is under a General Advisory. You will need to do your own snow stability assessments when using avalanche terrain in Huntington. A danger of falling ice exists, and will persist until it all comes down.

Clouds will thicken today before some snow showers develop late this afternoon and into the evening.  Early sun will give way to the potential for fog and decreased visibility. A summit high of about 20F with NW winds from 40-60+mph will be the warmest it will get over the next couple of days.  Temperatures should fall to about 10F tonight and only rebound slightly tomorrow with continued stiff winds to keep the mountain wintery and cold. There are still some isolated areas of newly deposited windslab from recent new snow that Tuesday’s cold air and high winds did little to consolidate. Remember to constantly re-evaluate each new area of cold slab you enter and not presume it was as stable as the last one you traveled through.  This is particularly true on steeper or in more protected terrain features from W and NW winds.   Additionally, be thinking about your changing fall line and runout. A small slab that knocks you off your feet may not bury you, but the consequences of a fall can be severe.

Crevasses, undermined snow, and waterfall holes continue to be a serious threat. Currently the area from the Sluice to the Center Bowl is littered with crevasses. Most of these are covered with a thin coating of newer snow, which makes them nearly impossible to safely assess their exact location, size and depth. The hazards presented by the crevasses are not to be taken lightly; it is truly “no-fall” terrain. Taking into account the extent of crevasses, the severity of the consequences, and the inability to assess the hazard, the greater Lip area, which includes a section of the summer hiking trail should be avoided entirely.  As we have discussed in past weeks this is also true for the heavily crevassed areas in the northern portions of the Center Bowl underneath the headwall ice, Lip and areas towards the Sluice all the way down to the Ravine floor.

Surfaces will be icy and hard below the new snow, so long sliding falls continue to be another significant threat. The slick surface will allow for rapid acceleration down slope, potentially sending you into numerous obstacles below you. An ice axe, full 10-12 point crampons, and real mountaineering boots are absolutely critical for climbing in these conditions safely. The hard surface beneath the new snow makes belayed climbing on the steeper slopes a wise technique. Because the current surface conditions have made most steep slopes “no fall” territory, the ability to use technical mountaineering skills and equipment effectively is imperative.

Even though temperatures this week will not be very warm, falling ice is a possibility as sun heats the dark colored rock. There is a lot of recently formed ice from the cold weather over the past couple weeks. Your best defense against falling ice is to avoid being anywhere near the possible runouts. The locations at greatest risk for this hazard are the Sluice, Lunch Rocks, the Lip, and the Center Bowl. Other areas aren’t immune though, so always be aware of what’s above you.  The Harvard Cabin is now closed for the season. The only camping permitted on the eastern side of Mount Washington is at Hermit Lake Shelters. The Sherburne Ski Trail is open about 1/3 of the way down; please cross over to the hiking trail at the rope.

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, the caretaker at Hermit Lake Shelters. 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

4-04-2012 Print Friendly

Avalanche Advisory for Tuesday, 4-3-2012

This advisory expires at 12:00 midnight, April 3, 2012

Tuckerman Ravine has Low avalanche danger. Natural and human triggered avalanches are unlikely except in isolated terrain features. The Lobster Claw, the Lower Snowfields, and the Little Headwall are not posted due to lack of snow. Huntington Ravine is under a General Advisory. You will need to do your own snow stability assessments when using avalanche terrain in Huntington. A danger of falling ice exists, and will persist until it all comes down.

With the exception of pockets of new snow in numerous places, recent snows have made little progress developing new slabs across large areas. On Sunday night, Mt. Washington received about 4.4” of very light density snow. Yesterday we thought this snow might be loaded into unstable slabs in the lee areas of Tuckerman. Although there was significant amounts of blowing snow along the ridges yesterday, slab development in the ravine was kept to a relatively small amount. There are isolated areas of newly deposited windslab. Each one you travel through may be different than the last, and they may be reactive to human triggering, so you should be assessing them individually. Additionally, be thinking about the fall line and runout. A small slab that knocks you off your feet may not bury you, but the consequences of a fall can be severe.

Currently, the springtime hazards are a little different than most years, due in large part to the thin snow coverage this season. Crevasses, undermined snow, and waterfall holes are a serious threat. Currently the area from the Sluice to the Center Bowl is littered with crevasses. Most of these are covered with a thin coating of newer snow, which makes them nearly impossible to safely assess their exact location and depth. The hazards presented by the crevasses are not to be taken lightly; it is truly “no-fall” terrain. Taking into account the extent of crevasses, the severity of the consequences, and the inability to assess the hazard, I highly recommend avoiding the Lip area entirely, which includes the area of Tuckerman Ravine hiking trail.

Surfaces will be icy and hard below the new snow, so long sliding falls continue to be another significant threat. The slick surface will allow for rapid acceleration down slope, potentially sending you into numerous obstacles below you. An ice axe, full 10-12 point crampons, and real mountaineering boots are absolutely critical for climbing in these conditions safely. The hard surface beneath the new snow makes belayed climbing on the steeper slopes a wise technique.  Because the current surface conditions have made most steep slopes “no fall” territory, the ability to use technical mountaineering skills and equipment effectively is imperative.

Even though temperatures this week will not be very warm, falling ice is a possibility as sun heats the dark colored rock. There is a lot of recently formed ice from the cold weather over the past couple weeks. Your best defense against falling ice is to avoid being anywhere near the possible runouts. The locations at greatest risk for this hazard are the Sluice, Lunch Rocks, the Lip, and the Center Bowl. Other areas aren’t immune though, so always be aware of what’s above you.

The Harvard Cabin is now closed for the season. The only camping permitted in the Cutler River Drainage is at Hermit Lake Shelters. The Sherburne Ski Trail is open about 1/3 of the way down and is in surprisingly good shape. Cross over to the hiking trail at the rope.

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, the caretaker at Hermit Lake Shelters.
  • 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

2012-04-03 Print Friendly

Avalanche Advisory for Monday, 4-2-2012

This advisory expires at 12:00 midnight, April 2, 2012

Tuckerman Ravine has MODERATE and LOW avalanche danger. The Sluice, Lip, Center Bowl, Chute, and Left Gully have Moderate avalanche danger.  Natural avalanches are unlikely and human triggered avalanches are possible. Right Gully and Hillman’s Highway have Low avalanche danger. Natural and human triggered avalanches are unlikely except in isolated terrain features. The Lobster Claw, the Lower Snowfields, and the Little Headwall are not posted due to lack of snow.

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

Well, we’re back into avalanche forecasting mode again. The mountain picked up 4” of light density snow (3.6%) yesterday afternoon and evening while winds remained virtually non-existent. This left behind a blanket of fluff that may act as a weak layer for future slabs to build onto. We expect this scenario to play out today, as winds will increase in velocity and shift from the N to the NW, ending the day in the 45-60mph (72-97kph) range. Through the day, the wind will be working to pick up and transport the snow that is currently sitting in the alpine zone. I suspect some of the new snow will be able to hide out in the rocks and vegetation, which will prevent loading from being as robust as it might be if we were in mid-winter conditions up high. But while there might be some limitations to what is available, I’m confident that there is sufficient snow to build new windslab. The key to understanding today’s avalanche danger is that the trend is for increasing avalanche danger through the day. Windloading will move most areas up through Low and into Moderate territory. Only time will tell for certain how far up the scale we go today. It may be into the upper end of the Moderate rating, or if loading is truly limited, it may just barely make it above Low.

In addition to the avalanche potential today, there are other significant hazards you need to be aware of, some of which are a little different this season than most years. Crevasses, undermined snow, and waterfall holes are a serious threat. Currently the area from the Sluice to the Center Bowl is littered with crevasses. Many of these are covered with a thin coating of newer snow, which makes them nearly impossible to safely assess their exact location and depth. We spent a lot of time yesterday looking into these problem areas, and I personally came away from the experience with a strong sense of humility and fragility. The hazards presented by the crevasses are not to be taken lightly; it is truly “no-fall” terrain. Taking into account the extent of crevasses, the severity of the consequences, and the inability to assess the hazard, I highly recommend avoiding the Lip area entirely, which includes the area of Tuckerman Ravine hiking trail.

Surfaces will be icy and hard below the new snow, so long sliding falls are another significant threat. The slick surface will allow for rapid acceleration down slope potentially sending you into numerous obstacles below you. An ice axe, full 10-12 point crampons, and real mountaineering boots are absolutely critical for climbing in these conditions safely. The hard surface beneath the new snow makes belayed climbing on the steeper slopes a wise technique.  Because the current surface conditions have made most steep slopes “no fall” territory, the experience and skills to use technical mountaineering equipment is imperative.

The Harvard Cabin is now closed for the season. The only camping permitted in the Cutler River Drainage is at Hermit Lake Shelters. The Sherburne Ski Trail is open about 1/3 of the way down and is in surprisingly good shape. Cross over to the hiking trail at the rope.

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, the caretaker at Hermit Lake Shelters.
  • 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

 2012-04-02 Print Friendly