Frank Carus

Apr 172014
 

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

Apr 162014
 

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