Avalanche Advisory for Friday April 18, 2014

This Advisory expires at midnight.

Tuckerman Ravine has Low avalanche danger. Natural and human triggered avalanches are unlikely except in isolated terrain features. These pockets do exist particularly from the Lip through the Center Bowl. Other secondary pockets exist in other locations such as in the Sluice, on the traverse between the Sluice and the Lip, etc. It is important to understand there is still potential to trigger a pocket from midweek’s snow, albeit isolated.

Huntington Ravine is under a General Advisory. 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: Wind deposited snow across the Center Bowl, and especially in the Lip area, that occurred on Wednesday is still the primary concern. These Wind Slabs stabilized a bit yesterday as temperature flirted with the freezing mark under bright sun. Higher temperatures in avalanche terrain today, perhaps close to 40F, will likely move cold wind slab issues towards a Wet Loose and thin Wet Slab concern.

WEATHER: Clear conditions and good 100 mile visibility with temperatures just below freezing made for a nice “winter” day on Thursday. Today, summit temperatures should break the freezing mark while increasing clouds start to knock down solar gain influence this afternoon. Winds from the S will move to the SW and increase to 40+mph (64kph). Looking forward, snow showers overnight and colder air will be in place tomorrow, but we’ll discuss that more in this afternoon’s Weekend Update.

SNOWPACK: +/-2” of rain on Tuesday followed by sub-zeroF temperatures created a bomber concrete snowpack by Wednesday that would have taken a trigger of planetary proportions to cause avalanches. A couple of inches of snow that fell since then are the problem now that Frank discussed yesterday, and I mention above. Slabs are scattered around primarily in the Center Bowl and Lip and are not to be walked into blindly, but don’t quite make into the Moderate rating. This is due to their overall lack of widespread continuity, size in the steepest terrain, the snow surfaces texture allowing good adhesion, as well are the generally roughness of the surfaces caused by the weekend traffic. Rain did knock down the size of bumps in the Lip, etc. but all these types of features are assisting in keeping new snow in place. Again, have an eye open for instability and do your stability tests to have good information to help your choices. A prudent and thoughtful user can avoid problems with some flexibility.

Additionally, be sure to consider new snow may be covering the beginning of developing crevasses and holes. Some of these drifts may be obscuring possible deep slots that opened during recent heavy rain and warm temperatures. You are most likely to find these on steep snow slopes beneath buttresses of rock or ice in the Headwall/Lip and Sluice areas. Be aware of the potential to punch through into these slots. The main waterfall hole, marking the Lip/Center Bowl boundary, opened during the rain storm, but some thin ice and snow is now concealing the hazard from view. The Open Book waterfall hole in the fall line of the Lip, 2/3rds the way down towards the floor, could make a sliding fall extremely consequential. Choose your line carefully!

OTHER HAZARDS: 1. Micro-spikes and other creeper style traction devices may be helpful on some lower angle trails, but they simply are not adequate for steep terrain! Be prepared for steep, firm snow and fast, icy surfaces. A fall on steep terrain today on the old surface would be next to impossible to self-arrest. Don’t fall especially above a crevasse or streambed. 2. Warm conditions will return the ice fall menace! The Sluice ice, behind Lunch Rocks, make this a horrible place to sit. Ice fall across the Lip through the Center Bowl is also looming waiting to be heated. Next to sliding falls this has been out #2 injury maker over time. Do not linger in their runouts! 3. Recent rain and warm weather really melted out snow spanning streams like the one that flows out of Tuckerman. With our deep snowpack, the distance from snow surface to rushing streambed below could make it difficult to climb out of some of the holes should you fall in. 4. The Sherburne ski trail is what you would expect after 2″ of rain followed by freezing temperatures. You can still make it to the parking lot but expect detours around ice, large bumps, bare spots and open water drainages.

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 0815. 4-18-2014. A new advisory will be issued tomorrow.

Christopher Joosen, USFS Snow Ranger.

2014-04-18 Print

Avalanche Advisory for Thursday, April 17, 2014

Tuckerman Ravine has Moderate and Low avalanche danger. Lip and Center Bowl have Moderate avalanche hazard. Natural avalanches are unlikely and human triggered avalanches are possible. All other forecast areas have Low avalanche hazard. Natural and human triggered avalanches are unlikely. Evaluate snow and terrain carefully!

Huntington Ravine is under a General Advisory. 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: Wind deposited snow across the Center Bowl and especially in the Lip area yesterday. These Wind Slabs will most likely be reactive to human triggering as they warm this morning before their energy is cooked out by the sunshine. The Open Book waterfall hole in the fall line of the Lip could make a sliding fall extremely consequential. Pockets of new wind slab also exist beneath Sluice ice, in Chute and below the narrow section, on skiers left, in Left Gully.

WEATHER: Two inches of snow yesterday blew into the Ravines on high, westerly winds. Light winds this morning coupled with clear skies will allow temperatures to push up into the 30’sF, if not into the 40’s, in Tuckerman today with upper 20’s F forecast for the summit. Scattered clouds could allow slopes to refreeze at times today with the temperature so close to freezing.

SNOWPACK: Snow surfaces not covered with new snow today will be very hard and icy this morning. Yesterday, winds from the west effectively transported the small amount of new snow into smooth wind slabs in the Lip, beneath the ice across the Headwall. Some of these drifts may be obscuring possibly deep slots that opened during recent heavy rain and warm temperatures. You are most likely to find these  on steep snow slopes beneath buttresses of rock or ice in the Headwall/Lip and Sluice areas. Be aware of the potential to punch through into these slots, especially when traveling on foot. The main waterfall hole marking the Lip/Center Bowl boundary opened but some thin ice and snow is now concealing the hazard from view. Choose your line carefully!

OTHER HAZARDS:  Recent rain and warm weather really melted out snow spanning streams like the one that flows out of Tuckerman. With our deep snowpack, the distance from snow surface to rushing streambed below could make it difficult to climb out of some of the holes should you fall in. Rain also weakened frozen waterfalls so keep this hazard on your radar. Lunch Rocks is still a roll of the dice in terms of this hazard.

Micro-spikes and other creeper style traction devices may be helpful on some lower angle trails, but they do not provide the security of crampons. Be prepared to handle steep, firm snow and fast, icy surfaces. A fall on steep terrain today would be next to impossible to self-arrest. Don’t fall today, especially above a crevasse or streambed.

The Sherburne ski trail is what you would expect after 2″ of rain followed by freezing temperatures. You can still make it to the parking lot but expect detours around ice, bare spots and open water drainages.

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 7:45 a.m. 4-17-2014. A new advisory will be issued tomorrow.

Frank Carus, Snow Ranger
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2856

2014-04-17 Print friendly

Avalanche Advisory for Wednesday, April 16, 2014

Tuckerman Ravine has 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 traveling in avalanche terrain in Huntington. A danger of falling ice exists, and will persist until it all comes down.

AVALANCHE PROBLEM: Plunging temperatures overnight are freezing our snow pack and beginning to lock up free water. A small amount of new snow (<1″) with continued upslope snow may create small pockets of unstable Wind Slab in lee areasThis morning, high winds are likely scouring high start zones and depositing snow lower in the Ravines. As winds slow later, look for the potential for wind slab development in higher start zones. Monitor the amount of new snow fall today and anticipate a potentially growing hazard, particularly if more upslope snow falls than is forecast.

WEATHER: The summit temperature graph was bearish last night, to say the least. Temperatures dropped to -2F (-19C) from a steady 40F (4C) last night at 6pm. Cold frontal passages like the one we are experiencing often spawn upslope snow shower activity on the mountain, though the Obs is only calling for a trace to one inch (2.5cm) of new snow today. Winds are blowing pretty steadily around 90 mph (115 kph) this morning. NWS point forecast is for 115 mph (185 kph) gusts this morning. Either way, it is pretty darn windy out. NW winds should fall off to 30-45 mph (50-70 kph) by sunset with clearing skies and temperatures rebounding a bit to the mid-single digits F (+/-  -15C).

SNOWPACK: To sum it up, hard and icy everywhere and undermined in many areas. If weak layers deep in the snowpack remain intact after the warm spell, they will be thoroughly bridged over by a icy skin of frozen slush and cold hard slabs of melt forms in the upper layers. The 2.18″ of rain that fell in the past 36 hours have opened waterfall holes and crevasses and undermined snow bridges covering water channels. Despite the cold, water is still flowing and continuing this process so if you venture into the Ravines be aware of the potential for punching through into these voids which can be surprisingly deep. Some thin areas in Right Gully and Sluice and areas over high volume water courses like the Lip and Center Bowl could collapse. The Little Headwall is now a waterfall. The Lip/Center Bowl waterfall hole and a crevasse along the base of the ice opened up on Monday and likely grew yesterday. I wouldn’t be surprised to see a slot lower near the top of the Open Book when visibility improves later today.

OTHER HAZARDS:  Today, we are standing at the busy intersection of winter and spring hazards. Cold temps and high winds coupled with open waterfall holes and icy trails make travel in the mountains challenging. Recent rain and warm weather really melted out snow spanning streams like the one that flows out of Tuckerman. With our deep snowpack, the distance from snow surface to rushing streambed below could make it difficult to climb out of some of the holes.

Micro-spikes and other creeper style traction devices may be helpful on some lower angle trails, but they do not provide the security of crampons. Be prepared to handle steep, firm snow and fast, icy surfaces. A fall on steep terrain today would be next to impossible to self-arrest. Don’t fall today, especially above a crevasse or streambed.

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 7:55 a.m. 4-16-2014. A new advisory will be issued tomorrow.

Frank Carus, Snow Ranger
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2856

2014-04-16 Print friendly

Avalanche Advisory for Tuesday, April 15, 2014

This advisory expires at 12:00 midnight.

Tuckerman Ravine has Considerable avalanche danger. Natural avalanches are possible and human triggered avalanches are likely. Dangerous avalanche conditions will exist after rainfall begins. Careful snowpack assessment, cautious route finding and conservative decision making are essential.

Huntington Ravine is under a General Advisory. 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: Potentially heavy rain today will create the potential for Wet Slab avalanches. The largest of these would be most likely to occur in the Sluice, Lip and Center Bowl area if the larger water courses overflow their channels and run out over deeper slabs or ice lenses. The greatest chance of these types of avalanches will be later in the day after the rain has penetrated more deeply through the snow and melt runoff increases beyond it’s already high levels. Most other forecast areas will share this problem so if skiing in the rain is your thing, consider lift service today.

WEATHER: Rain should begin this morning and pickup in intensity into the afternoon. An inch of rain will fall before changing over to snow late tonight and in the wee hours of Wednesday. Temperatures, now standing at 42F will start to decline in the late afternoon and evening to around freezing at sundown and then down to around 10F by morning. 1-3″ snow may fall by morning. SW Wind will ramp up a bit from it’s current 45 mph or so as rain increases in intensity before slowing a bit later in the day. Overnight wind will shift to the NW and crank up to the 80-100 mph range by morning. Expect temperatures well below normal tomorrow.

SNOWPACK: Todays rain will be falling on an already rotten, unsupportive snowpack. Even packed trails will have the potential for postholing as water channels beneath the melting bonds between snow grains. All the warm weather has weakened the snowpack and encouraged the inevitable downhill creep of the snowpack. Smaller crevasses near rocks were opening over the past several days but were minor compared to what you could expect to see today. The main waterfall hole that opened yesterday in the Lip/Center Bowl area makes a crossing of the Tuckerman Ravine trail a dangerous proposition.

OTHER HAZARDS: Rain and more warm temperatures today continue to flood streams and undermine snow. Larger stream channels like the brook coming out of Tucks can be dangerous. Imagine falling into a treewell with water rushing through the bottom…..just as hard to get out of and with hypothermia and drowning a real possibility. To spice things up further, icefall potential will be on the rise today making Lunch Rocks an especially bad choice of places to hang out and enjoy the cold, wind driven rain.

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. 4-15-2014. A new advisory will be issued tomorrow.

Frank Carus, Snow Ranger
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2856

2014-04-15 Print friendly

Avalanche Advisory for Monday, April 14, 2014

This advisory expires at 12:00 midnight.

Tuckerman Ravine has 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 traveling in avalanche terrain in Huntington. A danger of falling ice exists, and will persist until it all comes down.

AVALANCHE PROBLEM: The Low avalanche danger today is a result of multiple days of warm weather and cold nighttime temperatures. This diurnal cycle adds a lot of strength to the snow surfaces and reduces the potential for avalanche activity to a point where we are comfortable calling the danger level “Low.” Understand that predicting avalanches is not a perfect science. With this in mind, when traveling in avalanche terrain we always recommend carrying avalanche rescue equipment, practicing safe travel rituals, and keeping your awareness up for situations that could increase your risk.

WEATHER: If you’ve had any doubts about whether spring would ever arrive, today should be enough to erase them thoroughly. Valley temperatures may hit 70°F. The temperature sensors along the Auto Rd are already reading over 50°F at the 4300’ elevation! Higher summits forecasts for today call for the mountains to be in the clouds, but currently this is not the case. Even so, you should be ready for visibility to decrease if the cloud levels drop during the day.

Yesterday we received a surprise of about 2” of new snow at Hermit Lake before precipitation turned over to ice pellets and rain. At this point in the season, we will take whatever we can get to keep the existing snowpack fresh. It also highlights the ability of mountain weather to be somewhat unpredictable, so it’s best to be prepared for poor weather even if forecasts look promising.

SNOWPACK: We are certainly into a springtime snowpack. The ravines have spent far more time above freezing than they have below freezing over the last 24 hours. Today you should be expecting all surfaces to soften with the intense warming. Some slopes may turn into deep and unsupportive slop as well. Melt water may find its way to lower layers in the snow and produce a wet slab avalanche. My thoughts are that this will be more of a problem with Tuesday’s rain than with only melt water today.

OTHER HAZARDS: We are at the beginning of the icefall season, which means that there is a lot of ammunition perched high on the cliffs of the ravines. Sitting at Lunch Rocks is a lot like looking down the barrel of a loaded gun. You don’t want to be there when heat and sunshine pull the trigger. Other springtime hazards, such as undermined snow and crevasses, are emerging as well. If you’re planning a future trip to the ravine, do your homework about these issues in advance!

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 7:45 a.m. 4-14-2014. 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

2014-04-14 printable

Avalanche Advisory for Sunday, April 13, 2014

Tuckerman Ravine has 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 traveling in avalanche terrain in Huntington. A danger of falling ice exists, and will persist until it all comes down.

AVALANCHE PROBLEM: Recent daily melt and freeze cycles have brought our avalanche hazard down to Low. Today’s small amount of rain and warming are unlikely to create much avalanche danger. That said, safe travel practices and avalanche safety equipment are still a good idea. Avalanches caused by rain and warming are notoriously hard to predict, so a savvy mountain traveler will respect this threat by minimizing exposure with careful route finding.

WEATHER: Current temperatures are hovering around freezing at Alpine Garden elevations this morning and in the mid-30’s at Hermit Lake. Freezing rain and then rain are likely today. Up to a 1/4″ of rain may fall with temperatures on the summit eventually reaching 40 F by afternoon. This morning, freezing rain is predicted with winds coming from the southwest at around 40 mph, increasing to around 60 mph with higher gusts this afternoon.

SNOWPACK:  The snow pack is really beginning to shows signs of spring. Folks enjoyed the heck out of Tuckerman yesterday. About 1800 folks. Friday nights freeze was not very deep so all it took to soften things up was some sunshine with sluff piles and moguls showing up in short order. Shady aspects near the rims refroze quickly as the sun began to set. A little rain and freezing rain today may help smooth things out a bit. While generally stable, the issues that keep us search and rescue ready are still out there. There are still potential weak interfaces between wind slabs deep in the snowpack that can be lubricated and weakened by water. We saw this last year on a busy day when a wet slab pulled out of the Lip/Center Bowl waterfall area and surprised a lot of people near Lunch Rocks. A flood watch has been issued until Wednesday for the region so this hazard, along with undermined snow, crevasses opening up and sketchy stream crossings are all coming. Huntington Ravine climbs will continue to be exposed to rock and ice fall hazard due to warming.

OTHER HAZARDS: Icefall from the Sluice onto Lunch Rocks is becoming a real threat. Some of the ice over the “Knife edge” ridge between Sluice and Right Gully looks like it could fall any day.  Continued melting has really softened snow spanning streams like the exit from Tuckerman. As the volume of running water increases so does the hazard. Micro-spikes and other creeper style traction devices may be helpful on some lower angle trails, but they do not provide the security of crampons. Be prepared to handle steep, firm snow and fast, icy surfaces.

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. 4-13-2014. A new advisory will be issued tomorrow.

Frank Carus, Snow Ranger
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2856

2014-04-13 Print friendly

Hikers stuck on Lion Head

After climbing through Tuckerman Ravine earlier in the day, a pair of hikers descending Lion Head Winter Route each slipped and fell in the steep section of the route (independent of each other). Neither person was injured in the fall. However, having not hiked this trail before, they did not know how much farther down they would need to descend before the trail became less steep. They had appropriate clothing for the winter, but they fell short of being fully prepared. They had no ice axe or crampons, and they were wearing lightweight sneakers with microspikes and a different brand of slip on traction. They were able to make a call to 911 to ask for help with the descent.A Snow Ranger and four volunteer Ski Patrol members responded from Hermit Lake. At the scene, they encountered the hikers near the bottom of the steep section. One hiker was at the top of the rock step and the other was approximately 75′ uphill. The lower of the two was able to descend with some coaching and a hand line. The upper hiker was given an ice axe and downclimbed while on belay through the steep section. They were both transferred to Pinkham by USFS snowmobile.This is a common scenario that plays out every spring. Thankfully, this event ended without injury. The pair did need to endure several hours with cold wet feet due to wearing mesh sneakers- but thankfully again, they had spare socks and shoes in their vehicle. A couple of the points we discussed with them after the fact included:

  • Winter/Spring conditions take longer than summer hiking times. Leaving Pinkham at 1:15 put them at a disadvantage early on.
  • Making the mistake of thinking lightweight traction devices are the same thing as crampons. They also did not carry ice axes, although one did make a comment along the lines of “I’m glad I had my knife. It was the only thing that stopped my fall.” Similar to microspikes vs. crampons, a pocket knife does not offer security in steep terrain as an ice axe does.
  • Not carrying or using a map. When asked from a distance, the pair responded that they did not know if they were on the trail or not (they were). They apparently hiked up through Tuckerman, presumably in the Lip bootpack, then at the summit asked other hikers which was the fastest way down. They chose Lion Head over the Auto Road since it was the shortest distance, but despite following blue plastic blazes, they had thought they may have lost the trail after descending below treeline.

April 12th was the date of the Friends of Tuckerman Ravine race, the Son of the Inferno. This annual event draws a large crowd. We counted about 1850 people entering the Hermit Lake courtyard from the Tuckerman Ravine trail from around 8am to 3pm (thanks, Alec!) Also, this number does not count the hundreds that hiked up Lion Head or went into Huntington Ravine. For this many people to have spent the day on Mt. Washington and only have had four incidents is remarkable. Surely a lot has to do with luck, but we want to take a moment to thank the hundreds or thousands of you who did your homework, came prepared, were self-reliant, and went home with all your bones and soft tissues intact. We also want to thank the Mount Washington Volunteer Ski Patrol for all their help, not only on Inferno day, but each and every weekend from March through May. This is an incredible group of people who give a remarkable amount of time so that we all can better enjoy our days in the Ravine. Be sure to thank them when you get the opportunity!

Avalanche Advisory for Saturday, April 12, 2014

This advisory expires at 12:00 midnight.

Tuckerman Ravine has 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 traveling in avalanche terrain in Huntington. A danger of falling ice exists, and will persist until it all comes down.

AVALANCHE PROBLEM: The Low avalanche danger today is a result of multiple days of warm weather and cold nighttime temperatures. This cycle adds a lot of strength to the snow surfaces and reduces the potential for avalanche activity to a point where we are comfortable calling the danger level “Low.” Understand that predicting avalanches is not a perfect science. With this in mind, when traveling in avalanche terrain we always recommend carrying avalanche rescue equipment, practicing safe travel rituals, and keeping your awareness up for situations that could increase your risk.

WEATHER: Today’s weather forecast is for generally pleasant weather, but don’t forget that safely spending time in the mountains requires more preparation and equipment than a pleasant day in the park. For example, bring some extra dry layers, a jacket, and don’t forget the sunblock! Temperatures are starting today down below freezing, but elevations all the way to the summit should rise up above the freezing mark before long. Cloud levels will be dropping late, so if you’re out on the mountain when this happens (intentionally or otherwise) be ready for poor visibility and maybe some icy surfaces.

SNOWPACK: Overnight, cold temperatures put a good freeze on the surface layers in the ravine. Icy surfaces should be expected both early today and late, after slopes become shaded temperatures start to fall. An ice axe and crampons are recommended for travel on steep slopes. Micro-spikes and other creeper style traction devices may be helpful on some lower angle trails, but they do not provide the security of crampons. Expect to find an isothermal snowpack to a significant depth. Deep beneath the surface, you may be able to find some buried weak layers or interfaces between cold wind slab. We don’t feel that these are major players in the avalanche danger at this time, but a heavy rain event or prolonged warm spell may bring them back to the forefront of our minds.

OTHER HAZARDS: We are at the beginning of the icefall season. Smaller pieces of falling ice have been observed in a variety of locations in both Tuckerman and Huntington. Even small piece of falling ice can be very dangerous, so be alert for this hazard. Other springtime hazards, such as undermined snow and crevasses, are on the cusp of emerging, but so far have not been much of a threat.

FOR MORE INFORMATION ABOUT ANY OF THE POTENTIAL HAZARDS ON THE MOUNTAIN, CHECK IN WITH A SNOW RANGER OR SKI PATROL MEMBER.

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. 4-12-2014. 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

2014-04-12 Print Friendly

Avalanche Advisory for Friday, April 11, 2014

This advisory expires at midnight.

Tuckerman Ravine has Moderate and Low avalanche danger. Sluice, Lip, Center Bowl, Chute and Left Gully have Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible. All other forecast areas 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 traveling in avalanche terrain in Huntington. A danger of falling ice exists, and will persist until it all comes down.

AVALANCHE PROBLEM:  Heat penetrating into the snowpack, as well as some more rain, has the potential to weaken remaining deeper weak layers today. This means that Persistent Slabs are our primary avalanche problem. The Lip, Center Bowl, Chute and, to a lesser extent, Left Gully are the areas that carry the greatest risk. Though the probability of triggering one of these slabs is low, I would not want to be caught by the resulting debris. Minimize your exposure to this risk by traveling out of the fall line. Thin Wet Slabs from wind slabs which developed in the past 36-48 hrs in Moderate rated areas are also a potential concern though they carry less consequences than the deeper weak layers. Wet Loose sluffs are likely and will happen on most steeper terrain today.

WEATHER: The summit recorded .14″ of freezing rain last night with nothing in the collection can at Hermit Lake. Temperatures at Ravine elevations have been around 40F for the past 24 hours. Today’s forecast calls for more shower activity this morning before limited clearing begins this afternoon. West winds will drop from 50-70 mph to 30-45 mph through the day. Temperatures around 20F tonight will bring a good freeze up to restore the upper snowpack. Generally a warm but gloomy day is on tap.

SNOWPACK: Avalanches have mostly cleaned out the January 11 rain crust/facet layer but smaller areas still exist as do other deep wind slab interfaces. This 24 hr period of warm temperatures and rain is a pretty strong stressor so heat may reach these deeper layers for the first time. Shadier aspects have certainly not seen this degree of heating yet and many of the warm sunny days we have seen so far this year did not wet the snow much deeper than 40-50 cm down. This leads me to be suspicious of the Moderate rated slopes. This is the kind of hazard that can potentially reward a person who habitually practices safe travel techniques and minimizes exposure time. Skiing one at a time, climbing the extreme margins of gullies, and not waiting in the runout for others to descend are all wise choices.

OTHER HAZARDS: Slopes and gullies can change from soft and forgiving to icy and refrozen depending on subtle variations in aspect and snowpack. This can limit penetration of boots or skis therefore crampons and an ice axe are recommended for travel on steep slopes. Micro-spikes and other creeper style traction devices may be helpful on some lower angle trails, but they do not provide the security of crampons. Be prepared to handle steep, firm snow and fast, icy surfaces. Icefall can be a problem at times and though we are not into peak heating and associated icefall hazard yet, we are definitely seeing daily cycles of smaller icefall events. Huntington Gullies can spawn rockfall pretty readily with this amount of warmth and rain.

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. 4-11-2014. A new advisory will be issued tomorrow.

Frank Carus, Snow Ranger
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2856

2014-04-11 Print friendly

Avalanche Advisory for Thursday, April 10, 2014

This advisory expires at midnight.

Tuckerman Ravine has Moderate and Low avalanche danger.  Sluice, Lip, Center Bowl, and Chute have Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible. All other forecast areas have Low avalanche danger. Natural avalanches and human triggered avalanches are unlikely. Look out for small avalanches in isolated areas or extreme terrain.

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

AVALANCHE PROBLEM: New Wind Slab formed high in the lee areas from snow that fell yesterday. High in the Chute, as well as just above and below the ice in the Center Bowl and Lip are where these slabs could exist in a potentially dangerous thickness. Though unlikely to bury you, they could hurt you if you triggered one and were pushed into rocks or over an ice cliff. These wind slabs could turn into Wet Slabs later. Incoming heat energy and later in the day, rain and mixed precipitation could add to instability by weakening and adding mass to the slabs. A distant third problem should still be considered. Though settlement has occurred with the recent warming trends, the steepest areas, especially those near watercourses, could heat enough to avalanche on deeper (>4′) weak layers. The top of Left Gully springs to mind due to a cornice and wind affected hang fire from earlier avalanche cycles. It is the kind of hazard that can potentially reward a person who habitually practices safe travel techniques and minimizes exposure time.

WEATHER:  Clear skies through mid-day should warm things up in the Ravines before clouds thicken and the latest round of precipitation moves in. Hermit Lake temperatures are edging towards the freezing mark from a low somewhere in the mid-twenties. Winds are currently out of the north around 40 mph and should slow further, warm and shift southwest. Later in the day they will ramp up into the 60-80 mph range on the summit  as the next cold front approaches, bringing with it another mixed bag of precipitation.

SNOWPACK:  Surface snow conditions are solidly refrozen following recent warming and last nights cold temperatures. Ambient air temperatures are predicted to rise through the day. Cloud cover will slow snowpack temperature gain so timing is everything today. NWS and MWOBs aren’t entirely in sync with the timing of incoming precipitation but my money is on some snowpack warming today as the high April sun can work pretty quickly. We are still at a crossroads with winter and spring hazards both showing their teeth depending on the time of day and quick blasts of wintry precipitation. A savvy traveller will account for this and be flexible with travel plans and pay close attention to snowpack details and changeable weather conditions and how the two play together.

OTHER HAZARDS: Slopes and gullies can change from soft and forgiving to icy and refrozen depending on subtle variations in aspect and snowpack. This can limit penetration of boots or skis therefore crampons and an ice axe are recommended for travel on steep slopes. Micro-spikes and other creeper style traction devices may be helpful on some lower angle trails, but they do not provide the security of crampons. Be prepared to handle steep, firm snow and fast, icy surfaces. Icefall can be a problem at times and though we are not into peak heating and associated icefall hazard yet, we are definitely seeing daily cycles of smaller icefall events. South facing Huntington Gullies can spawn rockfall pretty readily this time of year.

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. 4-10-2014. A new advisory will be issued tomorrow.

Frank Carus, Snow Ranger
USDA Forest Service
White Mountain National Forest
(603) 466-2713 TTY (603) 466-2856

2014-04-10 Print friendly