Avalanche Advisory for Tuckerman and Huntington Ravines

Posted 8:00 a.m., Friday April 8, 2011

Tuckerman and Huntington Ravines have LOW avalanche danger. Natural and human triggered avalanches are unlikely except in isolated terrain features.

If you missed yesterday’s incredible weather and snow conditions, don’ t worry, you’ll have another opportunity to get after it today. The weather today will be more or less a repeat of what happened yesterday–temperatures in the ravines hovering right around or below the freezing mark, sunshine warming slopes facing S and SE, and rather calm winds by Mt. Washington standards. Midweek new snow had blown in on strong W and NW winds after rain stopped falling on Tuesday. This new snow had caused some concern over the past two days, but after watching numerous skiers and boarders charging hard in the Chute, Lip, Center Bowl, Sluice, etc. yesterday, my concerns about the stability of this snow have been put to rest temporarily. A large part of the stabilization came as a result of solar gain. It’s worth remembering that aspects facing to the north do not receive much sun at all, and although less new snow can be found on these aspects what is there may have more stored elastic energy. Another way to say it is that cold slabs that don’t get much sun will have a greater sensitivity to triggering, but they are generally smaller and more isolated. Examples of this type of issue can be found at the tops of South Gully and in Dodge’s Drop. While we don’t forecast for Dodge’s it is a slide path that has a proven history of behaving differently than other areas of the ravine. It’s about 5000′ in elevation, faces due north, and new snow stuck to the steep avalanche starting zone. Personally, it’s not a run I’d drop into without first doing some stability evaluation.

As we move into the weekend the weather outlook looks quite good for the first half, then expect a change on Sunday. Experience tells us that when we have good stability and good weather projected a few days out, the mountains will be quite busy. Wherever it is you travel in the mountains, be aware of what is going on around you. Often the biggest hazard you’ll face is the other people on the mountain who may unknowingly be putting you at risk. Do your best to stay alert to all hazards this weekend, both natural and human.

The Harvard Cabin is now closed for the season. Camping in the Cutler River Drainage is only allowed at Hermit Lake Shelters. The John Sherburne Ski Trail has full coverage and is open all the way to Pinkham. However, the upper part of the brook between the Bowl and the Little Headwall isn’t skiable, which forces skiers into the trees for a short stretch. Please be kind to the vegetation as you exit the Bowl, and be careful that you don’t end up taking an unexpected polar bear club dip into the brook!

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 caretaker at Hermit Lake Shelters. 
  • This advisory expires at midnight. 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

2011-04-08

Avalanche Advisory for Tuckerman and Huntington Ravines

Posted 8:40 a.m., Thursday April 7, 2011

Tuckerman Ravine has MODERATE and LOW avalanche danger. The Lobster Claw, Right Gully, the Sluice, Lip, Center Bowl, and the Chute have Moderate avalanche danger.  Natural avalanches are unlikely and human triggered avalanches are possible.  Heightened avalanche conditions exist in specific terrain features. Evaluate snow and terrain carefully to identify areas of concern.  Left Gully, Hillman’s Highway, the Lower Snowfields, and the Little Headwall have Low avalanche danger.  Natural and human triggered avalanches are unlikely except in isolated terrain features.

Huntington Ravine has LOW avalanche danger. Natural and human triggered avalanches are unlikely except in isolated terrain features.

Finally a stunning morning on the mountain!  It doesn’t seem that we have been treated to a lot of these this winter which makes them all the more inspiring when they arrive.  With the high pressure settling in overhead it should be quite a nice next 48 hours before things slowly change over again the second half of the weekend.  It will be a blue bird day today, but don’t shut off your keen avalanche awareness detectors because we have some fresh cold slabs to be aware of this morning.  Over the past 36-48 hours (Tuesday night into yesterday morning) the Summit received 3.5” (8.75cm) of cold snow on high winds.  Brian and I found about 3” (7.5cm) around the cabins by 7am Wednesday after the summit had only recorded about half that amount.  Based on these morning observations, periods of S1 and S2 (1-2cm an hour) snowfall intensity rates between 7 and 9 o’clock, and some afternoon snow, we believe avalanche terrain likely saw just a bit more snow than the summit recordings.  This snow was associated with average winds between 40-60mph (65-97kph) from the W and NW with temperatures climbing up out of the low single digits F, ideal conditions to move new soft slab into some E facing aspects.

What we are seeing this morning is a classic yin and yang between the two Ravines.  Huntington has solid Low avalanche conditions with pockets of new snow in Central Gully and high in the northern side of the Fan.  Over in Tuckerman, Hillman’s Highway and Left Gully have some limited new snow that should be watched, but generally they have been scoured down to old surface.  This changes rapidly as you move from the Chute over towards the Sluice.  Old hard surfaces exist under the Chute and down low under the climbers left half of the Center Bowl.  Up high above the narrows in the Chute, across the steepest parts of the Headwall in the Center Bowl, and particularly in the Lip and Sluice new cold soft slab conditions exist.  The Lip and Sluice are the areas of most concern this morning and I consider them in the upper half of the Moderate rating due to their avalanche potential in reaction to a human trigger.  Through the morning hours they will retain their cold snappy nature which should subside a bit later this afternoon.  Although clear sunny conditions with dropping winds will allow directly south facing slopes to pick up some solar gain, helping them start to stabilize, this won’t be as true for SE and E facing aspects.  Therefore the Lobster Claw, Right Gully, and portions of the Sluice will likely see some stabilizing later today, but I would remain suspicious of the Lip and the climbers left side of the Sluice closest to the Lip due to their SE and E nature.

The Harvard Cabin is now closed for the season. Camping in the Cutler River Drainage is only allowed at Hermit Lake Shelters.

Please Remember:

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

Printable Advisory

Avalanche Advisory for Tuckerman and Huntington Ravines

Posted 8:10 a.m., Wednesday, April 6, 2011

Tuckerman Ravine has Considerable avalanche danger.  Natural avalanches are possible and human triggered avalanches are likely.  There are two exceptions to this rating.  The Lower Snowfields have Moderate avalanche danger.  Natural avalanches are unlikely and human triggered avalanches are possible.  The Little Headwall has Low avalanche danger.  Natural and human triggered avalanches are unlikely.

Huntington Ravine:  Central, Pinnacle, Odell and South Gullies have Considerable avalanche danger.  Natural avalanches are possible and human triggered avalanches are likely.  All other forecast areas in Huntington Ravine have Moderate avalanche danger.  Natural avalanches are unlikely and human triggered avalanches are possible.

Today’s ratings are similar to yesterday’s but for completely different reasons.  Concerns about rain and warmth creating unstable snow conditions have faded with the invasion of a cold front.  Today we are back into a mid-winter like snow event with light density snow being blown into lee areas of the ravines.  Cold air kicked out the sub-tropical temperatures around mid-day yesterday and rain transitioned to snow.  We now have around 3″ (7.5 cm) of new light density snow and we are expecting anywhere from a trace to 2″ (5cm) of additional accumulation today.  WNW winds are exceeding 80 mph (129 kph) on the summit but are forecasted to back down to 45 to 60 mph (72 to 97 kph).  These forecasted wind speeds will be ideal for transporting new snow into both ravines forming wind slabs.  I suspect new wind slabs are going to be easy to trigger and there may be enough wind loading of the new snow to result in some natural avalanches as well.  The most likely area for natural avalanche activity is in the Sluice, Lip and Center Bowl in Tuckerman Ravine.  Given the low water content of new snow and recent winds, I think you will find a lot of variability in surface conditions today.  The older snow that has recently refrozen will likely be exposed in areas that are not protected from wind.  This is easily identified by its grayish color and icy surface.  While this snow is now stable, don’t be lulled into thinking you will find that in more sheltered areas.

High pressure will move in tonight and it looks like we will have a few days of decent weather.  Snow stability issues will be limited to what is occurring today and clear weather will give us a good opportunity to assess the extent of these issues tomorrow morning.  I know that spring skiing is on many of your minds and this window looks like the first good opportunity to capitalize on spring-like conditions.  Realize that icy conditions are dominating the mountain and we may have lingering avalanche concerns.  Hopefully this will change but you need to be prepared for winter.

The Harvard Cabin is now closed for the season. Camping in the Cutler River Drainage is only allowed at Hermit Lake Shelters.

Please Remember:

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

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

Printable Advisory

Avalanche Advisory for Tuckerman and Huntington Ravines

Posted 8:10 a.m., Tuesday, April 5, 2011

Tuckerman and Huntington Ravines have CONSIDERABLE avalanche danger today.  Natural avalanches are possible and human triggered avalanches are likely. The only exception to this rating is the Little Headwall which has Low avalanche danger.  Natural and human triggered avalanches are unlikely.  Undermined snow may become and issue in this area today.

A warm wind is rattling the cabin and brief bursts of rain are splattering on the window as I type.  This weather is the reason both Ravines have Considerable avalanche danger today.  It is currently 48 F (9C) at Hermit Lake and our upper snow pack is soggy.  Settlement patterns are visible in the Ravines and there is some evidence of recent wet loose avalanches that occurred within the new snow that fell yesterday.  These small avalanches were likely triggered by the transition to rain.  Over the past 24 hours Hermit Lake received 0.56″ (14.2mm) of water and the Summit recorded 1.22″ (31 mm) of water equivalent.  This came in the form of snow, sleet, freezing rain and rain.  Rain showers are expected to continue for the first part of the day before a cold front allows precipitation to transition back to snow.  Total water equivalents today are forecasted to be between 0.42 and 0.59″ (11 and 15 mm) with a trace to 2″ (5cm) of snow accumulation later in the day.  The warm weather and rain are keeping the threat of naturally triggered avalanches real.  Rain and melt water are percolating into the layered snow pack and weakening the strength of existing slabs.  As this continues, slab avalanches could occur and they could be pretty big. I was surprised to see that the warmth hasn’t penetrated very far into the snowpack at our snow plots as of this morning.  Our temperature readings were still below 0C at 10 and 20 cm into the snowpack.  (When enough free water makes it into the snow, you will get a reading of 0C in the snow.)  This makes me think that existing slabs in the Ravines still have plenty of cold snow to be irritated by the percolation that is occurring and will continue to occur with more rain on the way.  The type of avalanches we are concerned about today are difficult to predict.  At the end of the day, the Ravines may look the same or we may have large chunky debris piles and fresh fracture lines.  Due to the potential size and force of these avalanches, I would say it is wise to let this event pass before venturing into avalanche terrain.

A cold front will roll though today and temperatures up high will tumble into the teens F (around -9C) with NW winds increasing to 65 to 85 mph (105 to 137 kph) with higher gusts on the summit.  The return of cold air will start a trend toward stability in the existing snowpack and an icy surface will form.  We are expecting a trace to 2″ (5 cm) of new snow later today and another trace to 2″ (5 cm) falling overnight and into tomorrow.  While we can expect the current snowpack to become stable by tomorrow, we may have new dry snow avalanche concerns to focus on depending on how much new snow we actually receive.  If your planning on being on the mountain tomorrow you can expect icy conditions to dominate making crampons and an ice ax important tools to have in steep terrain.

The Harvard Cabin is now closed for the season. Camping in the Cutler River Drainage is only allowed at Hermit Lake Shelters.

Please Remember:

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

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

Printable Advisory

Avalanche Advisory for Tuckerman and Huntington Ravines

Posted 8:15 a.m., Monday, April 4, 2011

Tuckerman and Huntington Ravines will have CONSIDERABLE avalanche danger today.  Natural avalanches are possible and human triggered avalanches are likely. The only exception to this rating is the Little Headwall which has Low avalanche danger.  Natural and human triggered avalanches are unlikely.  Watch for unstable snow on isolated terrain features.

In the wake of a very winter like weekend, we find ourselves focusing on another storm system that will create new snow stability issues.  Unlike our last one that brought a foot of nice snow to the mountain, we will be dealing with a snow to rain situation.  We are starting off the day with Moderate danger in most areas with the gullies on the south side of Huntington still at Low.  We expect this to change today as snow falls on the mountain and is transported by increasing SW winds that will reach speeds of 50 to 70 mph (80 to 112 kph) with higher gusts by nightfall.  Total snow accumulation is forecasted to be between 2 and 4″ (5 and 10 cm) before transitioning to sleet and rain.  While this is a modest amount of snow, the increasing winds will be able to turn it into deeper wind slabs, especially on north and east facing aspects.  Temperatures are expected to climb today so new snow will likely become denser as the day wears on creating an upside down snowpack on all aspects.  This scenario will be our first concern that will cause our avalanche danger to increase to Considerable.  The second is the seemingly inevitable transition to all rain in avalanche terrain.   If you opt to thread the needle with the previously mentioned snow conditions, I would advise you get the heck out of avalanche terrain before it rains. Rain will cause instability to rise quickly in any new slabs that form today and it will start eating away at the strength existing wind slabs have.  These existing wind slabs are abundant and relatively new, having been deposited as recently as yesterday.  Rain is forecasted to continue tonight with periods of high intensity.  I expect peak instability to occur tonight with the potential for some large slabs to rip out due to the chaos the rain will bring to the layered snowpack in the Ravines.  Rain will continue into tomorrow before transitioning back to snow.  Expect elevated avalanche danger to linger through the day tomorrow.  Total water equivalent forecasted for the period, including what will fall as snow and mixed precipitation, ranges from around 1″ to 1.5″ (25 to 38 mm).

The Harvard Cabin is now closed for the season. Camping in the Cutler River Drainage is only allowed at Hermit Lake Shelters.

Please Remember:

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

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

Printable Advisory

Avalanche Advisory for Tuckerman and Huntington Ravines

Posted 8:00a.m., Sunday, April 3, 2011

Tuckerman Ravine: The Sluice, Lip, and Center Bowl have Considerable avalanche danger. Natural avalanches are possible and human triggered avalanches are likely. Lobster Claw, Right Gully, the Chute, Left Gully, Hillman’s Highway, and the Lower Snowfields have Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible. The Little Headwall has Low avalanche danger. Natural and human triggered avalanches are unlikely.

Huntington Ravine: North, Damnation, and Yale have Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible. All other areas have Low avalanche danger. Natural and human triggered avalanches are unlikely, however, watch for unstable snow on isolated terrain features.

The storm system that embraced the mountain over the past couple days has finally cleared out, and bluebird skies are allowing us numerous visual clues as to what took place yesterday under the thick cover of clouds and blowing snow. It’s the aftermath of the storm that provides today’s avalanche concerns. For the most part, the greatest concern comes in the way of human triggered avalanches. Three forecast areas in Tuckerman are rated Considerable today; these areas have a substantial amount of new windslab due to being protected from the NW winds. Yesterday’s winds were more gentle on these slopes than others, which results in relatively softer slabs and a greater potential for a person to trigger an avalanche here than in locations more exposed to strong winds. To further the case for Considerable, there is still low drifting snow blowing around in areas such as the Tuckerman headwall, the top of Hillman’s, and the Lion Head ridge. It’s not uncommon to have naturally triggered avalanches result from this type of windloading on a bluebird day. We expect this to subside in the afternoon, but until then we aren’t ruling out natural avalanche potential.

Locations posted at Moderate today have a wide variety of conditions. In some areas you’ll find hard wind effected snow or even wind scouring while in other locations you’ll find softer areas of fresh windslab. For example Left Gully has a wind scoured upper section but new snow has blown into the narrows and below. The more sensitive new slabs are most likely to be found on slopes with their backs to the NW winds, such as the climbers’ left sides of Lobster Claw and Right Gully and the top climbers’ right side of Hillman’s. Also be wary of transition areas between different conditions. This is often where unstable slabs can be thin and easy to trigger while having the potential to propagate out into deeper slabs. The last few weeks have changed the face of Tuckerman Ravine. Slopes are larger and more connected to one another than they have been all season, and runout paths are fully developed. You should think not only about stability directly underfoot, but also of what is going around you in adjacent areas.

In Huntington, the northern gullies all have clear evidence of avalanche activity, and they also have the largest stability problems. In addition to potentially unstable snow in the gullies themselves, the steep approaches to the ice may also have problems to watch out for. In the areas posted at Low, you’ll also want to be mindful of isolated pockets. There is currently spindrifting going on in the tops of most gullies that may be creating relatively small areas of windslab. The Harvard Cabin is now closed for the season. Camping in the Cutler River Drainage is allowed only at Hermit Lake Shelters.

Please Remember:

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

Printable Advisory

Avalanche Advisory for Tuckerman and Huntington Ravines

Posted 8:50 4-2-2011

Tuckerman and Huntington Ravines have HIGH avalanche danger.  Natural avalanches are LIKELY and human triggered avalanches are VERY LIKELY.  Very dangerous avalanche conditions exist.  Travel in avalanche terrain is not recommended. The only exceptions to this are the Lower Snowfields which has Considerable avalanche danger and the Little Headwall which has Moderate avalanche danger.

The summit picked up 12” (30cm) while we recorded about 10” (25cm) down at Hermit Lake.  During this snowfall winds have come from numerous points on the compass rose beginning from the SE through the E and to the N by around midnight.  Since then winds have settled into their favorite groove from the NW and rapidly increased with very brief spikes in velocity.  Winds were sustained between 70 and 80 mph peaking briefly at over 100 mph (160 mph). These speeds collapsed just as fast, falling down to 55-65mph where they currently sit, but are expected to rise a bit through the morning before subsiding again this afternoon gusting to 70mph.  The summit crew reported very large drifts and I have no doubt that although a lot of snow has moved already early this morning it will continue and load additional snow into the Ravines through the day.   In addition the Observatory is forecasting up to an additional 3” (7.5cm) of snow as upslope energy continues to produce precipitation for the mountains.  If this plays out the storm total would be close to 15” (38cm).

Runout paths have filled in through the season so avalanches from this storm may very well run farther than they have yet this season.  Many of these runout paths criss-cross each other in both Ravines so no place would be considered a safe to be therefore travel in avalanche terrain is not recommended.   Two areas posted below the High rating today are the Little Headwall at Moderate and the Lower Snowfields at Considerable.  The Little Headwall’s hazard will decrease rapidly with some skier traffic, but the initial users should exercise some caution realizing that a skier triggered avalanche is possible even though this forecast area is quite small and not too steep.  Skiers and riders may start to move into the Lower Snowfields which have some strong lee pockets to be cautious about and make good stability assessments before jumping in blindly.  Our main concern for this forecast area are the larger snowfields that exist under the Duchess.  Sluffing or a slab avalanche from the Duchess could trigger a slab in the Lower Snowfields, so although concerns exist towards the Little Headwall side of the forecast area its risk is slightly lower.

Summiteers have 2 main hazards to contemplate, the avalanche potential on the Lion Head Winter route and weather conditions above treeline bringing visibility close to zero at times.  I’ll focus on the avalanche issue.  Although the trail markers and bamboo poles designate the safest line through this area it is not without risk particularly during a storm and loading event like today.  Last weekend’s storm saw avalanche activity as little as 100ft from the route.  It is important to have good avalanche assessment skills to make smart well informed choices.  It will likely change through the day filling in footprints even if it sees a number of users.  Be very aware of anyone above you that could be a trigger.

The Harvard Cabin will close tomorrow so beginning Sunday night the only place to camp on the eastern side of Mount Washington is at Hermit Lake.

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.
  • This advisory expires at midnight. 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

Print Friendly Advisory

Avalanche Advisory for Tuckerman and Huntington Ravines

Posted 8:40a.m., Friday, April 1, 2011

Tuckerman Ravine: Lobster Claw, Right Gully, the Sluice, Lip, Center Bowl, and the Chute have CONSIDERABLE avalanche danger. Natural avalanches are possible and human triggered avalanches are likely. Left Gully, Hillman’s Highway, and the Lower Snowfields have Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible. The Little Headwall has Low avalanche danger. Natural and human-triggered avalanches are unlikely.

Huntington Ravine: North, Damnation, Yale, Central, and Pinnacle gullies have CONSIDERABLE avalanche danger. Natural avalanches are possible and human triggered avalanches are likely. Odell, South, and the Escape Hatch have Moderate avalanche danger. Natural avalanches are unlikely and human triggered avalanches are possible.

Let’s set aside the nuances of today’s weather for just a moment and focus on the most important piece of information. A Winter Storm Warning is in effect until 10pm. The trend today is for INCREASING AVALANCHE DANGER THROUGHOUT THE DAY AND OVERNIGHT. We’re starting the day with good stability in most locations, but this will change as Mother Nature drops her load across most of New England. We’re expecting 5-7″ (13-18cm) during the day and 2-4″ (5-10cm) more overnight. With the temperatures we’re seeing up on Mt. Washington, we expect the snow to be lighter in density here than it will be down in the valleys. This will help allow the winds to pick up the fresh snow and transport it into the ravines. Today’s winds are forecasted to increase in speed through the day as they wrap around from the ESE, moving to the NE, and coming from the NNW by 8pm or so. As the shift happens, loading and cross-loading will begin to take place on top of the thin blanket of new snow that’s already fallen. Into the night the increasing trend will continue. Most areas will push into the upper end of their ratings by the end of the day and will surpass today’s ratings at some point in the night.

Today’s stability issues will be most prominent and develop most quickly on S-facing slopes such as North and Damnation Gullies in Huntington and Lobster Claw and Right Gully in Tuckerman. However, expect significant cross-loading to occur on E aspects (e.g. the Center Bowl, Central Gully or Pinnacle) particularly late in the day when winds have shifted to a more northerly direction. Even relatively small E aspects may have unstable snow that could produce natural avalanches as the day progresses. Examples of this would include areas forecasted at Moderate today, such as the climbers’ right sides of Hillman’s, Left Gully, or South Gully. Although we believe this is unlikely to be the case until late today or into this evening, we aren’t ruling out the potential. Remember, the forecasted ratings are limiting in that they represent the avalanche danger in just one word. Today you will do well to pay attention to the big picture that is going on around you.

Expect tomorrow’s danger rating to be elevated, as winds will continue to shift towards the NW and remain fairly strong into tomorrow. This pattern is far more typical of winter weather than springtime, so if you’re thinking about spring skiing conditions you may want to look elsewhere tomorrow. We’ll update you tonight on the Weekend Update section of our website.

The best line up the Lion Head Winter Route at treeline is marked with bamboo poles. Evidence of recent avalanche activity can be found on both sides of the route. Shifting winds tonight will continue to fill in these steep snowfields. Stay on the marked path to avoid the more significant avalanche terrain on either side.

The Harvard Cabin will be closing for the season after Saturday night. Beginning April 3rd, the only place you may camp on the east side of Mt. Washington will be at Hermit Lake Shelters in Tuckerman 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.
  • This advisory expires at midnight. 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

Printable Advisory

Avalanche Advisory for Tuckerman and Huntington Ravines

Posted 8:30 Thursday 3-31-2011

Tuckerman Ravine has Moderate and Low avalanche danger.  The Lobster Claw, Sluice, Lip, Center Bowl, the Chute and the Lower Snowfields have Moderate avalanche danger.  Natural avalanches are unlikely and human-triggered avalanches are possible.  Right Gully, Left Gully, Hillman’s Highway, and the Little Headwall have Low avalanche danger. Natural and human-triggered avalanches are unlikely in these areas.  Watch for unstable snow on isolated terrain features.

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

Even though the sun finally popped out yesterday, winds kept slopes cool allowing some instabilities from last weekend’s storm to linger.  This event gave us about a foot of low density snow which has been transported since on NW winds.  Loading diminished to become insignificant on Wednesday as we enter a brief lull until tomorrow’s weather maker. The main areas of concern continue to be the Lip and the Center Bowl followed by their outliers, namely the Sluice and the Chute. The Lobster Claw has stable snow along the climber’s far right side which is also where most of the gully’s traffic has been.  The upper reaches of the climber’s right fork and the entire left fork from the bottom of the “Y” have more snow of concern and is the cause for the Moderate rating.  Brian and I were impressed with the amount of snow the Lower Snowfields picked up during the prolonged loading event following the weekend storm.  It is on the lower end of the Moderate rating, but not quite down to Low.  You will find a lot of spatial variability in this diverse forecast area that stretches from Hillman’s Highway to the Little Headwall.  Hillman’s Highway has pockets of snow to be aware of particularly in some isolated locations in the climber’s right hand fork.  In Right gully the climber’s left wall, which has an easterly aspect, have some isolated terrain features to watch.

The big news is the impending Winter Storm bearing down on the Northeast.  The National Weather Service (NWS) has issued a Winter Storm Warning from 2 am Friday morning until 8pm.  This Nor’easter has good agreement between models so we are confident we are in for a wallop. Initially snow will be lighter density with low wind speeds from the East.  Wind speeds will ramp up a bit before the shift towards the N occurs, likely moving snow from the earlier thin blanket.  I would expect cross-loading on W and SW slopes to occur during this period.  As daylight appears tomorrow snowfall intensity will increase, snow density will get heavier, and winds will increase to 60+mph (97kph) as they begin to shift and come from the NNW.   Total snowfall may surpass 12” (30cm) at higher elevations.  The NWS is forecasting 8-15” (20-38cm) for the region.  You will likely see a number of “High” ratings tomorrow with the potential for a Considerable or two, or even…… yes the “E” word…..Extreme.  If the system continues to pan out as expected travel in avalanche terrain will not be recommended tomorrow.  I would also expect lingering avalanche issues into the weekend with some elevated danger ratings.

The Lion Head Winter Route is filling in and evidence of recent avalanche activity can be found on both sides of the route.  The best line up the ridge is marked with bamboo poles.  Stay on this path to avoid the more significant avalanche terrain on either side. Saturday night April 2nd will be the last night the Harvard Cabin will be open this season.  After that, the only place you can camp on the east side of Mt. Washington will be at Hermit Lake Shelters in Tuckerman 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.
  • This advisory expires at midnight. 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

Printer Friendly Advisory

Avalanche Advisory for Tuckerman and Huntington Ravines

Posted 8:00 a.m., Wednesday, March 30, 2011

Tuckerman Ravine has Moderate avalanche danger.  Natural avalanches are unlikely and human-triggered avalanches are possible.  The only exceptions to this rating are the Little Headwall and Left Gully which have Low avalanche danger. Natural and human-triggered avalanches are unlikely in these areas.  Watch for unstable snow on isolated terrain features.

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

It has been a dynamic week with more weather expected to keep the show going.  Today and tomorrow morning are forecasted to bring a welcome lull in the active weather pattern before a Nor’easter impacts the region on Thursday night and Friday.  Today’s stability concerns are lingering wind slabs from last weeks 11.8″ (30 cm) of snow and a prolonged period of winter weather punctuated by relentless winds.  The mountain has been punishing lately and avalanche activity has been abundant.  The last storm, which was actually an unforecasted up slope snow event, produced our largest avalanche of the season in Tuckerman and numerous avalanches in terrain that hasn’t really had avalanche activity this season.  Natural avalanche activity calmed down on Sunday but we have had two natural avalanches since then that we know of.  The most recent of these occurred on Monday night when a sluff from the Duchess triggered a small slab in the Lower Snowfields.  Trace amounts of snow have fallen over the past two days which may have formed some softer slabs in strong lee areas of NW winds.  Of all the stability issues today, these will be the easiest to trigger but of less consequence than the hard slab that dominates Tuckerman.  The hard slab provides good bridging over weaker layers below and it could be challenging to trigger an avalanche.  If someone were to find a “sweet spot” that causes failure and fracture in the hard slab, expect a nasty avalanche to ensue.  Strong and sustained winds have created a mosaic of snow conditions that will require you to stay alert to changing conditions.  In Huntington, this mosaic exists but isn’t as complex as Tuckerman.  For the most part, Huntington has been pounded into a stable state by recent winds.  Tuckerman offers some options for the avalanche savvy traveler and clearing conditions should make it easier to make sense of what is going on.

We look forward to taking advantage of the clearing trend to better evaluate the current avalanche issues.  Expect similar stability ratings tomorrow with potential for some areas posted at Moderate to move down to Low.  As mentioned, we are starting to have more confidence that this next storm will bring accumulating snow to the mountains Thursday night and Friday.  Expect elevated avalanche danger to spill over into the weekend.  We will keep you posted on this in the coming advisories and in Friday’s weekend update to help you with your trip planning.

The Lion Head Winter Route is filling in and evidence of recent avalanche activity can be found on both sides of the route.  The best line up the ridge is marked with bamboo poles.  Stay on this path to avoid the more significant avalanche terrain on either side.

Saturday night will be the last night the Harvard Cabin will be open this season.  After that, the only place you can camp on the east side of Mt. Washington will be at Hermit Lake Shelters in Tuckerman 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.
  • This advisory expires at midnight. A new advisory will be issued tomorrow.

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

 Printable Advisory