Avalanche Advisory for Sunday, March 5, 2017

This advisory expires at Midnight.

Tuckerman Ravine has MODERATE and LOW avalanche danger. The Lip has 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. The Little Headwall is not forecast due to lack of snow.

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

AVALANCHE PROBLEM: Signs of natural avalanche activity occurring last night due to wind loading of the scant amount of snow that has fallen the past couple of days has raised concerns for human-triggered avalanches today. With the exception of the Lip and right side of Center Bowl, most of these wind slabs will be on the smaller side. Look for smooth areas of snow that will contrast easily with nearby old, gray snow or new, wind eroded sastrugi snow. Test these wind slabs for signs of instability before committing to the slope. The larger fetch upwind of Tuckerman made more snow available for larger wind slabs to develop in the Lip with pockets in Sluice and Center Bowl. Central Gully in Huntington also has pockets of wind slab that are bordering on the Moderate danger rating while most of the rest of the gullies are scoured.

WEATHER: Current temperature on the summit is -11F with -1F at Pinkham Notch. Wind is from the NW at 60 mph and will diminish a bit through the day to the 45-60mph range. The temperature will warm and ultimately reach 0F by the end of the day under sunny skies. Seems like a great summit day, with excellent visibility, if you keep your skin covered.

SNOWPACK: Signs of the recent warm up are largely gone and have been replaced by signs of winter. The waterfall hole in the Lip as well as the Little Headwall have refrozen and most of Huntington and much of Tuckerman Ravine are showing refrozen, hard snow surfaces. There is a surprising amount of new snow across the Headwall and Sluice so be sure to keep in mind that our snowpack and avalanche paths remain expansive and more than capable of producing dangerous avalanches when we get new snow. A crown line low in the Lip is a good reminder that wind slabs develop with even small amounts of snow this time of year when the plateau downwind of Tuckerman and to a lesser extent, Huntington, are smoothed out by a substantial snowpack. This means that every bit of new snow that falls can be transported by the wind into avalanche start zones in leeward areas.

OTHER HAZARDS:

  • Glide cracks, moats and crevasses have opened in places and are just concealed with new snow. The hole above the above the Open Book low in the Lip forecast area would be worth avoiding if traveling on foot.

Please Remember:

  • Safe travel in avalanche terrain requires training and experience. This advisory is just one tool to help you make your own decisions in avalanche terrain. You control your own risk by choosing where, when, and how you travel.
  • Anticipate a changing avalanche danger when actual weather differs from the higher summits forecast.
  • For more information contact the Forest Service Snow Rangers, the AMC at the Pinkham Notch Visitor Center, or the caretakers at Hermit Lake Shelters or the Harvard Cabin.
  • Posted  8:00 a.m., Sunday, March 5, 2017. 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

2017-03-05

Avalanche Advisory for Saturday, March 4, 2017

This advisory expires at Midnight.

Huntington and Tuckerman Ravines have LOW avalanche danger. All forecast areas have Low avalanche danger. Natural and human-triggered avalanches are unlikely. The Little Headwall is not forecast due to lack of snow.

AVALANCHE PROBLEM: Just over three inches (3”) of snow arrived over the past 48 hours on strong west winds, creating firm wind slab in areas of our terrain. This clean new snow will be easy to identify over the dirty, refrozen old surface. The largest pockets will be found just under the rollover of Tuckerman with scattered, smaller pockets in the lee areas of NW winds. With an inch of snow possible today, the wind slab may grow in size, but will not affect the stability of the snowpack. Many areas, including most of Huntington Ravine, are scoured down to old surface. What remains is a very icy textured surface. Any slip or fall today will accelerate quickly so be aware of this when moving around the mountain.

WEATHER: It is cold. The current ambient air temperature on the Summit is -23F and -5F at Hermit Lake. Combine this with a west wind of 57 mph to get a wind chill of -65F! Keep warm today as it will remain this cold until tomorrow morning. Another inch of snow arrived yesterday on top of the 2.3” on Thursday. This morning may bring an additional inch of snow. Clouds should linger for the day with increasing winds into the 80 mph range and shifting to the NW.

SPRING HAZARDS: While it may not feel like spring today, the thaw from last week left some of our snowpack with a springtime look to it. Be on the lookout for the following:

  • Glide cracks, moats and crevasses have opened in places and may now be concealed with new snow, making identifying these extra difficult.
  • Undermined snow over stream channels can be a problem in gullies but more of a danger lower in the tributaries. Lots of holes in snow covering the streams have opened and may be hard to see from above. Falling into one, especially with skis or board strapped on, could be disastrous. Exiting Tuckerman Ravine on skis is becoming more of a challenge than some of the skiing above.
  • The cold snap today will encourage flash freezing of water available in the system. Today’s weather is prime for ice dams releasing a fire hydrant onto unsuspecting climbers in Huntington. This can happen naturally, but is more likely to occur from an ice tool swung into a bulge, creating the crack that will allow pent-up pressure to explode.
  • Long, sliding falls are possible today. Self-arresting on the old surface will be difficult to say the least. Competency with crampons will make travel safe today.

 

Please Remember:

  • Safe travel in avalanche terrain requires training and experience. This advisory is just one tool to help you make your own decisions in avalanche terrain. You control your own risk by choosing where, when, and how you travel.
  • Anticipate a changing avalanche danger when actual weather differs from the higher summits forecast.
  • For more information contact the Forest Service Snow Rangers, the AMC at the Pinkham Notch Visitor Center, or the caretakers at Hermit Lake Shelters or the Harvard Cabin.
  • Posted  8:15 a.m., Saturday, March 4, 2017. A new advisory will be issued tomorrow.

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

2017-03-04

Avalanche Advisory for Friday, March 3, 2017

This advisory expires at Midnight.

Huntington and Tuckerman Ravines have LOW avalanche danger. All forecast areas have Low avalanche danger. Natural and human-triggered avalanches are unlikely. The Little Headwall is not forecast due to lack of snow. Skiing or riding from the Bowl is challenging now.

 AVALANCHE PROBLEM: High west and northwest winds transported yesterday’s 1.5-2” new snow into mid-slope start zones but scoured most other areas. The wind slabs of most concern will look smooth and white compared to the gray, old snow surface that was exposed by the wind scouring action of moving snow. These wind slabs will be firm, hard to trigger and relatively small in most areas but steeper places such as high in the Chute, or beneath the ice in Center Bowl or on the approach to Harvard Bulge ice, may have larger slabs to contend with. Areas in Tuckerman Ravine (Lip, Sluice, Center Bowl and Chute) with a strong east aspect that were most sheltered from the W and WNW winds and are downwind of the largest fetch zone, where snow is picked up and carried by those wind speeds, have the highest danger rating but are still Low. All other areas in both Ravines were heavily scoured.

WEATHER: Clear skies, good visibility and NW winds in the 60mph range currently grace the summit. The mercury now stands at -11F there with 10F at Pinkham Notch. Winds will blow from the west today in the 50-70 mph range on the summit which is a nice break from the 70-90 mph winds yesterday. The high temperature today will rise to around 0F in the early afternoon. Another cold front approaching this afternoon will bring falling temperatures with a slight increase in wind speeds. Expect colder conditions later this afternoon with increasing cloud cover, reduced visibility later in the day and falling temperatures reaching a low of around -25F by tomorrow morning.

OTHER HAZARDS: With the recent warm spell working on the snowpack, springtime hazards have emerged early though good coverage remains on most aspects. Expect the need for crampons in most of the steeper terrain, even on approaches. Be aware of the following other hazards today:

  • Ice dams – water flowing down Huntington gullies can build up pressure behind ice and burst from the force of an ice tool placement. This effect can be especially pronounced after a rapid swing in temperatures such as we have had.
  • Glide cracks, moats and crevasses have opened in places and may now be concealed with new snow, making identifying these extra difficult.
  • Undermined snow over stream channels can be a problem in gullies but more of a danger lower in the tributaries. The recent warmth and rain has streams flowing at a pretty good clip. Falling into one, especially with skis or board strapped on, could be disastrous.

Thanks to all the folks that turned out for our fundraiser last night at Allspeed Cyclery and Snow in Portland. Friends of Tuckerman Ravine, Black Diamond, Julbo, Mammut, Ski the East, Tuckerman Brewing, Black Point Surf Shop, and Wild Northeast magazine helped us out with prizes. Most everyone walked away with shwag and one lucky soul left with a new pair of Liberty skis! We’ll be doing this event again, for sure!

Please Remember:

  • Safe travel in avalanche terrain requires training and experience. This advisory is just one tool to help you make your own decisions in avalanche terrain. You control your own risk by choosing where, when, and how you travel.
  • Anticipate a changing avalanche danger when actual weather differs from the higher summits forecast.
  • For more information contact the Forest Service Snow Rangers, the AMC at the Pinkham Notch Visitor Center, or the caretakers at Hermit Lake Shelters or the Harvard Cabin.
  • Posted  7:50 a.m., Friday, March 3, 2017. 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

2017-03-03

 

Avalanche Advisory for Thursday, March 2, 2017

This advisory expires at Midnight.

Huntington Ravine has MODERATE and LOW avalanche danger. Central and Odell Gully have Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible. All other forecast areas will have Low avalanche danger with natural and human-triggered avalanches unlikely.

 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 and human-triggered avalanches are unlikely. The Little Headwall is not forecast due to lack of snow. Skiing or riding from the Bowl is challenging now.

 AVALANCHE PROBLEM: Lingering moisture in the atmosphere is bringing moderate snowfall to Hermit Lake this morning. This snow is likely to bond well to the old snow surface but weather changes today will create suspect layers in this new snow. Currently, high west winds are transporting snow into lee terrain. This wind will increase and shift to the northwest today, continuing to load mid-slope start zones and cross load others. Anticipate elevated danger from new wind slabs today especially if we meet or exceed the forecast snowfall totals.

WEATHER: A little over a third of an inch of rain fell on the summit yesterday before changing over and dropping a half inch of snow early this morning. Summit temperatures finally dropped below freezing shortly after midnight last night bringing the latest thaw to an end. Upslope snowfall will continue through the morning and we appear to be on track to receive the 1-3” amount that is forecast. A one-two punch of cold fronts will lead to a very cold and windy weekend. The first cold front will arrive today on a tight pressure gradient generating NW winds in the 100+mph range. Summit temperature is currently 16F and will fall to near 0F by dark and continue to fall overnight, reaching-10F tomorrow morning. Saturday morning’s low temperature could set a record.

OTHER HAZARDS: With the recent warm spell continuing to work on the snowpack, springtime hazards have emerged early this year. Falling temperatures last night will make long, sliding falls possible again today as surface snow begins to refreeze. Be aware of the following other hazards today:

  • Ice dams – water flowing down Huntington gullies can build up pressure behind ice and burst from the force of an ice tool placement. This effect can be especially pronounced after a rapid swing in temperatures such as we have today.
  • Glide cracks, moats and crevasses have opened in places and may now be concealed with new snow, making identifying these extra difficult.
  • Undermined snow over stream channels can be a problem in gullies but more of a danger lower in the tributaries. The recent warmth and rain has streams flowing at a pretty good clip. Falling into one, especially with skis or board strapped on, can be disastrous.

Please Remember:

  • Safe travel in avalanche terrain requires training and experience. This advisory is just one tool to help you make your own decisions in avalanche terrain. You control your own risk by choosing where, when, and how you travel.
  • Anticipate a changing avalanche danger when actual weather differs from the higher summits forecast.
  • For more information contact the Forest Service Snow Rangers, the AMC at the Pinkham Notch Visitor Center, or the caretakers at Hermit Lake Shelters or the Harvard Cabin.
  • Posted  8:15 a.m., Thursday, March 2, 2017. 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

2017-03-02

Avalanche Advisory for Wednesday, March 1, 2017

This advisory expires at Midnight.

 

Huntington Ravine and Tuckerman Ravine have LOW avalanche danger. Natural and human-triggered avalanches are unlikely in all forecast areas. Watch for unstable snow on isolated terrain features. The Little Headwall is no longer forecast this season as it is now an open river.

AVALANCHE PROBLEM: With the temperature warming and rain falling, Wet Slabs will be the main problem today. These will develop as the wind slab that formed Sunday is saturated with rain and melting snow. The largest pockets of this are just under the rollover in the Bowl in Tuckerman and can also be found in sheltered areas of terrain features in other locations. Wet slabs are very difficult to predict.  They can be triggered by the added weight of water to an existing slab; alternately, meltwater can lubricate a potential sliding surface within the slab or at the interface of the old surface. As rain continues to fall and increases in intensity, the possibility of triggering this layer will increase. However, the amount of rain forecast is light and will be spread out through the day, likely allowing the snow to absorb the water and remain in place. The rest of the snowpack spent much of last week above freezing and should handle the water today with no real problems.

WEATHER: Precipitation began last night and has delivered .06” of water to the Summit. Southwest winds of 40mph will shift to the W and increase to 65-80mph. All elevations are above freezing this morning with Hermit Lake already above 40F. The warm front setting up over the region may drive the Summit to the mid-40sF by the afternoon, possibly setting a new record high today. Rain will be light for most of the day with about 0.1” falling by dark and another 0.2” tonight.

SPRING HAZARDS: Warm temperatures are creating spring hazards sooner than usual. If recreating today, be on the lookout for the following:

  • The freeze/thaw over the past 48 hours will loosen rocks in exposed cliffs. This time of year is notorious for rock fall in steep terrain. The ice flows that formed over the winter are delaminating from the rock. Be aware of ice fall.
  • Ice dams – water flowing down Huntington gullies can build up pressure behind ice and burst naturally or more likely from the whack of an ice tool or crampon.
  • Glide cracks, moats and crevasses have opened and will increase in size with the melting taking place. The largest ones at the moment are under the cliff that separates the Sluice from the Lip, at the top of the early season ice climb called the Open Book, and on the approach to Central Gully near the climb called Cloudwalkers.
  • Undermined snow over stream channels can be a problem in gullies but more of a danger lower in the tributaries. The generally warm winter so far hasn’t allowed many streams to freeze so this undermining is emerging early this year. The Little Headwall is mostly open water, making exiting the Bowl on skis difficult.

Please Remember:

  • Safe travel in avalanche terrain requires training and experience. This advisory is just one tool to help you make your own decisions in avalanche terrain. You control your own risk by choosing where, when, and how you travel.
  • Anticipate a changing avalanche danger when actual weather differs from the higher summits forecast.
  • For more information contact the Forest Service Snow Rangers, the AMC at the Pinkham Notch Visitor Center, or the caretakers at Hermit Lake Shelters or the Harvard Cabin.
  • Posted  8:10 a.m., Wednesday, March 1, 2017. A new advisory will be issued tomorrow.

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

2017-03-01