Avalanche Advisory for Monday, December 31, 2012

Expires at 12:00 midnight, December 31th, 2012.

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

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

The pundits today may all be focused on Washington, but personally I think what’s going on here on Mt. Washington is more interesting and newsworthy. It’s been a while since we’ve seen winds sustained at such a strong speed, staying from the NW at 90+mph (145kph) for well over 15 hours with gusts up to 117mph (188kph). The forecast is for wind speeds to stay quite strong through today and this will play a significant role in snow stability during this forecast period. In case you’ve been hibernating for the last two weeks, winter has come on strong here, bringing December’s summit snowfall total to almost 70″ (178cm). About 22″ (56cm) of this has fallen in the past 4 days. How the wind has been moving this snow across the terrain is the reason for the difference in ratings for the two ravines.

In Huntington, I strongly suspect that the winds last night were able to scour and wind-hammer all of the forecast areas. This generally leaves behind either old surfaces, such as the December 21st rain crust, or very hard and strong windslab. However there is an exception to this. In locations that were heavily sheltered from the winds, relatively softer slabs may have developed, and these may be unstable.  Be watchful for any areas where you see signs of wind loading, for example an increase in the depth of your boot penetration may clue you in to snow with less strength. Further, as winds diminish late in the day there is a chance that what snow is left to be blown may actually stick to the slopes and create isolated areas of unstable slab. The bottom line for Huntington is to stay aware of the potential for isolated areas of unstable snow amidst a generally stable snowpack.

In Tuckerman a slightly different story is playing out. This ravine is more protected from the winds and less prone to scouring than Huntington, so concerns exist about ongoing loading of snow onto steep slopes. After Thursday’s storm, areas such as Right Gully and the Lobster Claw had about as much snow them as they did at their peak last season. The headwall area, Left Gully, and  Hillman’s were still a little bony, but snowfields were growing and connecting to one another. Virtually all other areas also had growing bed surfaces. I suspect that many forecast areas had avalanche activity yesterday, so slide paths are growing as well. Add all this to the continuation of blowing snow landing in the ravine, and you need to be thinking about the potential for naturally triggered avalanches to take place.

Although we are only expecting a trace amount, it’s worth mentioning that snow is currently falling at Hermit Lake. If we get more than a dusting, expect avalanche danger to be increasing and potentially exceeding the rating, particularly for Huntington.

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 8:45 a.m. December 31, 2012. 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

12-31-2012 Print Friendly

Avalanche Advisory for Sunday, 12-30-2012

Expires at 12:00 midnight, December 30th, 2012.

All forecast areas of Tuckerman and Huntington Ravines have HIGH avalanche danger. Natural avalanches are likely; human triggered avalanches are very likely. Very dangerous avalanche conditions exist. Travel in avalanche terrain is not recommended.

It appears as though 2012 will go out with a bang…or maybe more like the roar of a freight train passing by. Not only has there been above average snow over the last two weeks, but the weather conditions over the next 36 hours or so will be especially fierce. These are conditions that should make you seriously consider (or reconsider?) taking a trip above treeline. Winds today will be steadily on the rise, reaching sustained speeds over 100mph (162kph) before dark. During this time, temperatures will continue to fall to below zero F (-18C). In the evening the trend continues, with even stronger winds and colder temperatures.

As you can probably imagine by now, spending time up high on Mt. Washington today has the potential to be a very challenging experience. So while there may not be a lot of people moving around up there, snow certainly will be on the move today. As far as avalanches go, what will happen today seems pretty clear. It’s an almost perfect setup situation for numerous avalanches in many areas.

Last night about 6″ (15cm) of light density snow fell during a period with summit winds generally less than 30mph (48kph). This new snow blanketed any existing snowfields and lower angle ice bulges, creating a nice layer of weak snow as the first step toward this avalanche cycle. Next, winds shifted to the NW and began to rise. As the newly fallen snow was in the 5-6% density range, it didn’t need much wind to start loading it onto the weaker layer. Continually increasing winds overnight and through today are going to keep layering heavier, denser slabs on top of softer, weaker layers. We expect this scenario to play out in most forecast areas today, so although the size of the avalanches are not expected to be very large, there is a strong likelihood that a single avalanche path may slide several times today. As if last night’s snow wasn’t enough, today’s winds will be strong enough to pick up any and all available snow from the windward side of the mountain and load it onto the eastern slopes as dangerous windslabs.

Today is a good day to stay out of avalanche terrain. This includes venturing very far up onto the floor of Tuckerman. Yesterday I saw avalanche debris in Odell Gully that had run almost to the flats of Huntington. Despite what I said about expected avalanches to not be very large, there is no reason to believe today’s avalanche activity will not run into low angle terrain at the base of slide paths.

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. December 30, 2012. 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

Avalanche Advisory for Saturday 12-29-2012

Expires at Midnight Saturday, 12-29-2012

Tuckerman Ravine has LOW and MODERATE avalanche danger.  The Lobster Claw, Right Gully, Sluice, Lip, and Center Bowl have Moderate avalanche danger.  Natural avalanches are unlikely and human triggered avalanches are possible.  Evaluate snow and terrain carefully to identify features of concern.  The Chute, Left Gully, and Hillman’s Highway have Low avalanche danger.  Natural and human triggered avalanches are unlikely.  Watch for unstable snow in isolated terrain features.  We are not forecasting for the Lower Snowfields and the Little Headwall due to a general lack of snow. Forecasting will begin for these areas when conditions warrant although avalanche activity may occur before this point.

Huntington Ravine has LOW and MODERATE avalanche danger.  North, Damnation, Yale, Central and Pinnacle gullies have Moderate avalanche danger.  Natural avalanches are unlikely and human triggered avalanches are possible.  Evaluate snow and terrain carefully to identify features of concern.  Odell and South Gully have Low avalanche danger.  Natural and human triggered avalanches are unlikely.  Watch for unstable snow in isolated terrain features.  We are not forecasting for the Escape Hatch due to a general lack of snow. Forecasting will begin when conditions warrant.

Although no new snow fell during the day on Friday a brisk NW wind loaded Thursday’s Nor’easter storm snow back into the Ravines.  Although clear in the valley, we were desperately waiting out low visibility and blowing snow for a safe opportunity to get in the Ravines.  A brief window gave us some glimmers of Tuckerman, but Huntington’s view held out until this morning.  What we witnessed was enormous loading into S aspects from E, NE, and N storm winds.  This caused Connection Gully to avalanche and filled in the Lobster Claw and Right Gully. The Bulls-eye for new loading yesterday occurred on SE facing slopes.  A natural avalanche was triggered in the Lip during the early afternoon which ran down the “Open Book” and onto the Ravine floor.  Loading continued with strong NW winds into the early evening.  Another avalanche crown line was witnessed below the earlier fracture this morning which likely occurred during the overnight. 

The main points for today:

**Generally, many snowfields are still growing to their typical size and continue to be isolated from their neighbors by brush, rocks, and ice.   A good route finder with avalanche skills can find reasonable lines to avoid instabilities.  However, it is important to recognize we have had recent natural avalanche activity in such pockets, mostly focused on SE facing slopes and below ice bugles.  Therefore be cautious and evaluate new areas of slab from the recent storm, particularly in areas forecasted at Moderate.

**In Huntington be particularly aware of unstable slabs on some approaches particularly below large ice bulges.  This was demonstrated by an avalanche that occurred yesterday below the initial ice in Odell.

**Areas posted at Low do have isolated pockets of concern near the top of gullies such as the climber’s right of Hillman’s and Left gully.  Also watch pockets in the lee of terrain feature changes mid-gully such as above the narrows in the Chute and in the central low angle portions of Odell.

** New snow is expected to begin this afternoon and pick up late in the day.  Snow will continue during the overnight bringing us 3-5 inches by Sunday morning.  Winds will begin light and travel counterclockwise from the NW all the way around the compass rose back to the NW again tomorrow.  As it travels it is expected to increase in velocity and be raging in the morning gusting to 100mph.  We don’t expect this to affect danger ratings today during daylight hours, but start thinking about a change of conditions this evening if you’re out late.  Tomorrow you can expect avalanche ratings to increase.

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 8:34am 12-29-2012. 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

12-29-2012 Print Version

Avalanche Advisory for Friday, 12-28-2012

Expires tonight at midnight December 28th 2012.

Tuckerman and Huntington Ravines have CONSIDERABLE avalanche danger today. Natural avalanches are possible and human triggered avalanches are likely. Careful snowpack evaluation, cautious route-finding, and conservative decision-making are essential.

It’s pretty incredible to see firsthand how quickly Mt. Washington can evolve into a wintery landscape. As of two weeks ago, the summit had recorded only 6″ (15cm) of snow for the month of December. After yesterday’s storm, that total has soared to 63″ (160cm). Yesterday’s storm was a good one, dropping almost 16″ (40cm) on the summit and about the same at Hermit Lake. The exact numbers are disputable, because strong winds have drifted snow into our snow study plots lower on the mountain and forced the Observatory to partially estimate their totals. Without a doubt though, a lot of snow fell yesterday. Early in the storm winds were generally from the east, increasing towards 100mph (162kph) and gusting even stronger. They did subside some in the afternoon before making a swing around to the NW and ramping up again this morning.

Currently, winds are howling at Pinkham and Hermit Lake, pushing around a lot of snow and generally making life uncomfortable for those gearing up in the parking lot. Blowing snow is the chief concern for today and is driving the Considerable rating. What fell yesterday with the easterly winds is being pushed right back in the direction of the ravines today. NW winds are great at loading snow into all of our forecast areas, so the number one problem you’ll face in avalanche terrain is new windslab on the surface. We are hoping that the clouds clear out enough today to actually get to look at where recent snows were deposited and hopefully see evidence of some early season avalanche activity. If you’re heading for avalanche terrain today, take some extra time to think about your route choices. The east winds may have deposited snow in unusual locations, and new loading may be changing the overall loading pattern right before your eyes.

As we move closer to the weekend, you can expect diminishing winds early on Saturday, followed by the chance for some additional snowfall later in the day as well as on Sunday. We’ll post our first Weekend Update this evening on our website, www.mountwashingtonavalanchecenter.org. Be sure to keep up to date with the latest weather information and avalanche advisory before heading up the mountain.
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 8:45 a.m. December 28, 2012. 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

 

Avalanche Advisory for Thursday, 12-27-2012

Expires tonight at midnight December 27th 2012.

Tuckerman and Huntington Ravines will have HIGH avalanche danger today.  Natural avalanches are likely and human triggered avalanches are very likely on a variety of slope angles and aspects.  Very dangerous avalanche conditions exist and travel in avalanche terrain is not recommended.

It’s no secret that a major weather maker is impacting the area as we speak triggering a “Winter Storm Warning” until tomorrow morning.  Forecasted snow totals have vacillated back and forth a bit with each weather model run, but currently the mountains of NH are expecting 12-18” (30-45cm) with potential more in localized  areas.  This precipitation is being delivered on high ESE and E winds gusting in the 90-100mph (144-160kph) range this morning.  This will back off as the day progresses being a more effective loader of snow in our terrain versus the current scouring agent.  Our greatest concern today is the cross loading of N and S facing aspects which will become more unstable into the afternoon.  Although east facing aspects, such as the Tuckerman Headwall, will receive a much higher degree of scouring small terrain features on these aspects will also receive some cross loading depending on the exact wind direction.  Because of this it is important not to generalize too much concerning what aspects might being getting completely scoured.

It’s early in the season so there are a number of the typical locations that have limited bed surfaces.  The Lobster Claw, high in Right gully, North gully and South Gully are some examples of thin couloirs with multiple anchors scattered through their terrain.  They will take longer to reach the “High” forecast and may sit in the “Considerable” range for a good portion of the storm event flirting with the High danger definition.  However, copious amounts of low density snow rapidly loaded by high snowfall rates and wind will eventually make many anchors in these areas moot, hence the High rating.  The blanket rating today for the two Ravines is greatly hinged on the potential for far over a foot of snow.  Given the potential for atypical avalanche activity in locales that were a bushwhack yesterday, very high winds, and near zero visibility travel in avalanche terrain is certainly not recommended.  Depending how this storm event plays out we may return to not forecasting for some areas due to the lack of bed surfaces.   We’ll have to see how much snow we end up with and the exact duration of high velocity winds.

As this system moves into the Maritimes winds will wrap around through the NE, N and eventually out of the NW tomorrow.  As this move begins to occur overnight we expect South facing aspects to receive additional loading.  As our prevailing winds from the NW get settled in Friday morning a potential for new elevated avalanche concerns should develop tomorrow for aspects with an E and SE component.  Be sure to take a look at the latest avalanche information updated daily and, for a prelude to the weekend, our first Weekend Update on www.mountwashingtonavalanchecenter.org late Friday afternoon.

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 6:40a.m. December 27th, 2012. 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

12-27-2012 Print Friendly

Avalanche Advisory for Wednesday, December 26th 2012

Expires 12:00 midnight December 26, 2012

Tuckerman and Huntington Ravines have Moderate avalanche danger today.  Natural avalanches are unlikely and human triggered avalanches are possible.  We have not begun forecasting for the Lobster Claw, Right Gully, the Lower Snowfields, or Little Headwall in Tuckerman and the Escape Hatch in Huntington due to a general lack of snow in these areas.  Forecasting will begin for these areas when conditions warrant although avalanche activity may occur before this point.

This is the first 5 Scale U.S. Danger Rating Advisory of the season. Snow conditions have changed rapidly over the past week and clear skies are finally giving us the first view of the mountain we have had in quite a while.  The summit has received 42.2” (107cm) of snow over the past 10 days bringing us back to the normal range for the month.  Of this, 6.9” (17.5cm) fell yesterday with a low water content of 5% which was easily moved around in a number of gullies.  This has given us some concerns for touchy low density slabs peppered across both Ravines.  The rating of Moderate reflects this issue, but it is not a widespread concern or found in slabs of appreciable size. Because of this we are barely in the definition of Moderate and the savvy traveler with avalanche skills shouldn’t have trouble analyzing the terrain for a reasonable route.  The low density snow from yesterday will likely be the weak layer for the expected storm bearing down upon us from the south.  We will be in a WINTER STORM WARNING beginning tonight and stretching all the way until Friday morning.  Heavy snow will begin during the overnight and through tomorrow. The heaviest periods will be during daylight hours on Thursday accumulating in the neighborhood of 12” (30cm) or more. This will be brought in on building winds from the SE and the E.  These wind directions won’t cause the level of hazard that a westerly event does, but we should see a significant cross loading problems in our N and S facing gullies. Anticipate an elevated avalanche danger during the storm and potentially afterwards on Friday as wrapping winds should shift to our prevailing NW. This will cause new problems.  So….. here we go, winter is fully hunkering in and you’ll be hearing from us every day with a 5 scale danger rating forecast.  Hope you had a great holiday and we’ll talk to you tomorrow.

 Please Remember:

  • Safe travel in avalanche terrain requires training and experience. This advisory is just one tool to help you make your own decisions in avalanche terrain. You control your own risk by choosing where, when, and how you travel.
  • Anticipate a changing avalanche danger when actual weather differs from the higher summits forecast.
  • For more information contact the Forest Service Snow Rangers, the AMC at the Pinkham Notch Visitor Center, or the caretakers at Hermit Lake Shelters or the Harvard Cabin. Posted 8:33a.m. 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

12-26-2012 Print Friendly

General Advisory for Sunday, 12-23-2012

This is a GENERAL AVALANCHE ADVISORY for Tuckerman and Huntington Ravines.  A new General Advisory will be issued if conditions warrant or within 72 hours of this release.

A General Advisory is issued when there are limited instabilities within the entire forecast area. Snowfields in the ravines are growing in size and  unstable slabs may exist in these locations. Assessing snow stability for yourself as you travel through the mountains is always the right thing to do. Although we have not yet begun issuing daily danger ratings, avalanche activity may still occur. Remember that even a small avalanche from a small snowfield can be quite dangerous, especially in early season conditions such as these.

Overall on Mt. Washington, typical winter conditions were late in arriving. There was scant snow to be found in early December, but from Dec. 16th to the 22nd, the summit has reported a total of 32.2″ of snow. Unfortunately there were some warm temperatures, rain, and mixed precipitation during this time, so this number needs to be seen in the full context of what’s happened here. At lower elevations, we observed much less snowfall and more rain and melting. Around the mountain you’ll find a mix of surfaces, which may include water ice, breakable crusts, strong supportive crusts, and dust on crust, as well as areas where new snow has accumulated more deeply due to wind loading or funneling down a gully. Pay attention if you find an area where the snow has been able to accumulate, because it’s likely to be sitting on top of either a crust or on water ice, neither of which likes to bond well with new snow and could avalanche on you.

Looking ahead at the weather over the next few days, a high pressure system is in the cards, but this doesn’t mean sunny beach weather is here. Expect the weather to be cold and windy as low pressure exits on Sunday and Monday. Tuesday’s forecasts currently call for some light snow showers, but the real gift in Santa’s bag is on Wednesday night and Thursday. The NWS is talking about increasing confidence for a significant winter storm during this time. This may be the storm that pushes us into our daily forecasting routine, but it’s still several days away so we’ll have to be patient for now.

In case you were wondering, the Sherburne does have snow and is skiable from top to bottom. However, it is a backcountry trail, so there is a lot of brush and small trees that are not yet buried. There are also several water bars that contained open water as of Sunday, thanks to the rain on Thursday 12/21.

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 9:00, December 23, 2012.

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

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General Advisory for Friday, 12-21-2012

This is a GENERAL AVALANCHE ADVISORY.  A new General Advisory will be issued if conditions warrant or within 72 hours of this release.  This General Advisory pertains to both Tuckerman and Huntington Ravines.

A General Advisory is issued when there are limited instabilities within the entire forecast area. However, there are snowfields that are growing in size and may be unstable. Some examples in Tuckerman include Left Gully, the Chute and the smaller snowfields scattered between ice bulges across the Center Bowl. Some unstable slabs may be poorly bonded to the blue water ice below. Similar conditions may exist in the typical areas of water ice in the narrow Huntington gullies. Assessing snow stability for yourself as you travel through the mountains is always the right thing to do. Keep in mind that avalanche activity may occur before the issuance of a 5-scale forecast and if a snowfield is big enough to recreate on, it’s big enough to avalanche.

It sure has been a week filled with precipitation of all kinds. The higher summits picked up mostly snow with a bit of rain and sleet. Over the last 5 days the summit reports 16.2” (41cm) of snow and mixed precipitation for a total of 2.32” (6cm) of melted water. Snow began on the mountain on Friday in the very early morning. As of this writing, 5” (13cm) has fallen with winds from the south exceeding 70mph (112kph). Unfortunately, we expect most avalanche terrain will see some rain falling on top of the new snow. Rain on snow raises a lot of red flags for travel, even when snowfields are on the smaller side.

Over the weekend you can expect falling temperatures to turn precipitation back to snow. Winds are forecasted to become quite strong on Friday and Sunday, doing a fairly typical transition from a southerly flow on Friday to a more northwesterly direction Saturday and Sunday. The winds may move some newly fallen snow into avalanche terrain, so again I’d advise you to be prepared to make your own snow stability assessments as you travel in avalanche terrain.

At this time of the year new snowfall can make a remarkably rapid change in potential avalanche conditions, so start paying attention to the daily weather and new snow amounts. Be sure to check for the latest avalanche advisory before heading into avalanche terrain. Have a great ramp up into the holidays and maybe we’ll see you up here soon.

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 0930 12-21-2012. A new advisory will be issued when conditions warrant.

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

12-21-2012 Print friendly

2 Climbers Avalanched in Pinnacle Gully

Two climbers approaching Pinnacle Gully reported that they were swept down 70 to 100 meters from the start of the first ice pitch in Pinnacle Gully. In waist to chest deep snow the lead individual triggered the avalanche as he approached the ice from the north. The fracture occurred above the climber and was approximately 5 meters below the transition to steep ice. Neither climber was buried in the incident and no injuries were sustained.

General Advisory 12-18-2012

Expires Thursday at midnight, December 20th 2012

This is the initial GENERAL AVALANCHE ADVISORY for the 2012-2013 season. A new General Advisory will be issued if conditions warrant or within 72 hours of this release.  This General Advisory pertains only to Tuckerman due to the lack of snow cover in Huntington Ravine. Advisories for Huntington will begin when needed.

A General Advisory is issued when there are limited instabilities within the entire forecast area. However, there are snowfields that are growing in size and may harbor some instabilities. Some examples in Tuckerman include Left Gully and the Chute. These are the two areas in the Ravine that grow in size the earliest in the season and present the largest potential bed surfaces for future snow to load on. Yet, the smaller snowfields that develop in between ice bulges across the Center Bowl can be more problematic.  This can be true because the ice flows attract early season climbers, often “testing” more snow instability potentials.  Keep this in mind and don’t underestimate these smaller patches of snow on your chosen ice climbing route.  Many unstable slabs may be sitting on top of blue water ice with poor bonding at their interface.  In the early season when the mountain is under a General Advisory, you need to make your own avalanche stability assessments and evaluation before venturing into some of these questionable areas. Keep in mind that avalanche activity may occur before the issuance of a 5-scale forecast and if a snowfield is big enough to recreate on, it’s big enough to avalanche.

In anticipation of this first advisory day I took a look back to see how far behind we are this season.  To the surprise of my failing memory we are actually ahead of last year’s advisory writing by 5 days!   With that said the gifts of snow aren’t exactly falling out of old man Nick’s sleigh.  It’s hard not to take it a little personally as I self-examine what I did this year to deserve a big bag of coal (i.e. little snow and some rain.)   But I’m trying to put that behind me as we have entered a better precipitation pattern, now all we need is some cold temperatures to help it all be snow.  Sunday and Monday’s Mount Washington summit snow totaled to about 9” (22.5cm).  This is expected to be followed on Tuesday by snow, freezing rain and probably rain for avalanche terrain, perhaps heavy at times.  As cold air mixes back in Tuesday night into Wednesday snow is expected to return, giving the summits another 4-6”….maybe.   The main point to take home is we are in a new pattern of regular precipitation for the foreseeable future.  At this time of the year new snowfall can make a remarkably rapid change in potential avalanche conditions, so start paying attention to the daily weather and new snow amounts.  I am always impressed how quickly the landscape changes during this time of the season.

Check www.mountwashingtonavalanchecenter.org frequently as we move through late December and certainly check for the latest avalanche advisory before heading into avalanche terrain. We’re excited to be back at it and look forward to seeing you in the mountains!

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 0930 12-18-2012. A new advisory will be issued when conditions warrant.

Christopher Joosen, Snow Ranger
USDA Forest Service

2012-12-18 Print-friendly