Avalanche Advisory for Tuesday, December 16, 2014

This advisory expires tonight at 12:00 midnight.

All forecast areas of Tuckerman and Huntington Ravine have Low avalanche danger. Natural and human triggered avalanches are unlikely. Watch for unstable snow in isolated terrain features which may be capable of producing small avalanches.

AVALANCHE PROBLEM: Today’s avalanche problems will be any lingering pockets of wind slab or small wet slabs, depending on how quickly and how far temperatures drop during the day today. Low danger means conditions are generally safe, but it includes the possibility for unstable snow in isolated terrain features or in extreme terrain. In the current early season snowpack, pretty much all the snowfields except for a few can be considered “isolated terrain features” or “extreme terrain.” Wind slabs that developed this past Sunday have had time to stabilize, but I won’t rule out the potential for some instabilities to still be found out there, particularly in areas such as the Lip, Center Bowl, or Central Gully.

WEATHER: Yesterday the Mt. Washington Observatory recorded a max temperature of 41 degrees F (5C) and stayed above freezing for most of day and overnight. Temperatures at Pinkham Notch were down below freezing during this same period. Today we are expecting temperatures to drop slightly at the upper elevations. Increasing clouds will foreshadow a weather system moving in later tonight and sticking around until early Thursday. Keep your eyes on the summits weather forecasts if you are planning a trip for Wednesday or Thursday.

SNOWPACK: A prominent player in the snowpack discussion today is the elevation of the warm/cold line and, more importantly, just how warm the snowpack in the ravines in the last 24 hours. In this case, I would expect that warmth entering the snowpack has worked toward stabilization of previously existing wind slabs. If these became very warm and saturated wet, then the trend might have worked in the opposite direction as there would be a wet slab sitting on top of an ice crust or in some locations plain water ice, hence the discussion about the potential for pockets of unstable slab in isolated terrain features. I don’t want to get too bogged down in the nuances of warmth on snow, because I’m hopeful that falling temperatures will continue to strengthen the snowpack to where we will sit solidly in Low danger before long. Until lock-up happens, you should expect to find generally good stability with the potential for some small unstable slabs.

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. December 16, 2014. A new advisory will be issued tomorrow.

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

2014-12-16

Avalanche Advisory for Monday, December 15, 2014

This advisory expires tonight at 12:00 midnight.

Tuckerman Ravine has MODERATE and LOW avalanche danger. The Lip, Center Bowl, and Chute have Moderate avalanche danger. Natural avalanches are unlikely and human-triggered avalanches are possible. Lobster Claw, Right Gully, the Sluice, 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. Lower Snowfields and the Little Headwall are not posted due to lack of snow cover.

Huntington Ravine has MODERATE and LOW avalanche danger. North, Damnation, Yale, and Central have Moderate avalanche danger. Natural avalanches are unlikely and human-triggered avalanches are possible. Pinnacle, Odell, South Gully, and Escape Hatch have Low avalanche danger. Natural and human-triggered avalanches are unlikely. Watch for unstable snow in isolated terrain features.

AVALANCHE PROBLEM: Wind slab is the avalanche problem you are most likely to see today. For the most part, the terrain in the ravines is very discontinuous at this point early in the season. There are some larger snowfields with more continuous snow cover, but in most forecast areas you will be moving from one distinct patch of snow to another. This requires ongoing assessment of snow stability and solid route-finding skills to keep you away from unstable snow. Many areas posted at Low danger do have wind slabs that may be unstable. The primary differentiating factors between the Moderate rated locations and the Low rated areas are the size and distribution of the slab, not necessarily the likelihood of you triggering the snow.

WEATHER: If you are a fan of mild weather, today is your day. Temperatures will be rising above freezing all the way up to the summit while winds diminish to a gentle 5-20mph from the NW (Beaufort 3-4 for the nautical-minded). Warmth will persist through the night, until temperatures begin to fall back on Tuesday in advance of a weak weather system mid-week.

SNOWPACK: As already mentioned, one defining characteristic of the current snowpack is that it is very broken up. There are few large connected snowfields, which means that any avalanche that is triggered will be relatively small but can be quite dangerous. Areas posted at Low have more options for avoiding instabilities than those rated Moderate. In these conditions it can be quite tempting to take the “easier” route through the snow rather than the “safer” route that avoids instabilities, but I’d recommend choosing the less hazardous route unless you can confidently say that the snow has good stability.

Yesterday I spent some time in Tuckerman looking at the snow structure. What I found would be very disturbing if the ravine was more filled in than it currently is, and is certainly disturbing when found in exposed areas like the Lip or Center Bowl. There is slab at the surface that was formed during Sunday’s winds. This sits on top of a layer of light unconsolidated snow (read: weak snow). Beneath this is a sleet crust and other crusts. Stability tests at our location provided very easy results – CT0, CT0, ECTP4 – at the interface between the uppermost slab and the weak snow. As the columns popped off the pit wall, the weak snow layer was left intact on top of the crust. You should expect the depth of these layers to be quite variable as you move from one location to another.

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 15, 2014. A new advisory will be issued tomorrow.

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

2014-12-15

Avalanche Advisory for Sunday, December 14, 2014

This advisory expires tonight at 12:00 midnight.

Tuckerman Ravine has MODERATE and LOW avalanche danger. The Sluice, Lip, Center Bowl, the Chute, and Left Gully have Moderate avalanche danger. Natural avalanches are unlikely and human-triggered avalanches are possible. Lobster Claw, Right Gully and Hillman’s Highway have Low avalanche danger. Natural and human-triggered avalanches are unlikely. Lower Snowfields and the Little Headwall are not posted due to lack of snow cover. Watch for unstable snow in isolated terrain features.

Huntington Ravine has MODERATE and LOW avalanche danger. North, Damnation, Yale, Central, Pinnacle, and Odell have Moderate avalanche danger. Natural avalanches are unlikely and human-triggered avalanches are possible. South and Escape Hatch have Low avalanche danger. Natural and human-triggered avalanches are unlikely. Watch for unstable snow in isolated terrain features.

AVALANCHE PROBLEM: Wind slab is the primary avalanche problem for today due to recent snow being redistributed around the mountain by strong N and NNW winds yesterday. These slabs formed on a variety of potential bed surfaces, including water ice and ice crusts from the recent thaw as well as lighter density storm snow. Expect to find these slabs in lee areas and gullies which generally face south and east. They may be on the smaller side due to our early season snowpack, but they could pack a punch especially if the sweep you down rocky terrain. Slabs formed from sluffing and spindrifting snow (a.k.a. Loose-Dry avalanches) run a close second on the list of avalanche concerns. Expect these firm slabs beneath steep terrain features and approaches to steep pitches of ice.

WEATHER: Yesterday around 2.5″ (6 cm) of new snow were recorded on the summit though only a trace (.5 cm) was collected at Hermit Lake. Regardless of the total amount of new snow, strong wind transport occurred for a 4 to 5 hour period mid-day yesterday when winds were steady in the 50-60 mph (80-95 kph) range with gusts to 70 mph.

Relatively warm temperatures today will continue to improve snow stability. Today’s weather forecast marks a break from our unsettled weather due to the Low pressure which has been parked off the coast for the past week. Though temperatures will warm into the 30’s F at mid-elevations today, expect lingering clouds, flat light and some fog to hamper visibility at times. Wind from the NW will diminish to the 20-35 mph range, though gusts to 55 mph will remind you why you carry goggles and spare gloves here. The temperature on the summit at 8 am was a balmy 19F and will approach the freezing mark through the day. Enjoy the warmth while it lasts since the coldest month of the year is right around the corner.

SNOWPACK: Somewhere in the neighborhood of 2′ (60cm) of snow exists in wind sheltered areas of higher terrain. With the exception of the new snow (3-7″, depending on location) that has fallen in the past 48 hours, most of this snow is encapsulated by a stiff crust of refrozen snow. Beneath this crust another ice lens existed. Relatively warm temperatures have helped to further stabilize these deeper layers leaving us with wind slab and sluff slab as our main concern.

The summer Lion Head trail to the summit remains open and is the safer option than other choices on the east side of the mountain. A variety of hiking conditions exist, with traction devices, including crampons and ice axes, recommended, if not required for travel near and above treeline.

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 8:30 a.m. December 14, 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

2014-12-14 print friendly

Avalanche Advisory for Saturday, December 13, 2014

This advisory expires tonight at 12:00 midnight.

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

This is the initial Avalanche Advisory for the 2014-2015 season using the North American Public Avalanche Danger Scale (a.k.a. the “5-scale system.”) Bear in mind that the existing conditions and snow coverage are in a state of transition. We recognize that Considerable is a strong rating for the paths that are just beginning to fill in with snow, but in others where the bed surfaces are much more developed we feel this rating most accurately describes the potential hazard today. Naturally triggered avalanches are a possibility. You will need to be able to carefully assess the terrain as well as the snowpack in order to minimize your exposure to the hazard.

AVALANCHE PROBLEM: Wind slabs are the primary avalanche problem for today due to recent snow being redistributed around the mountain. Slabs will form on a variety of early season surfaces, including water ice and ice crusts from the recent thaw.

WEATHER: The weather on Mt. Washington has been substantially different than down in the valley over the last few days. Tuesday night we received a heavy dose of wet snow, which was followed up by some rain and mixed precipitation. Following this the temperature lowered and we began to receive snow. Approximately 5″ (12.5cm) were measured at the summit since Thursday morning. Today’s forecast calls for an additional 1-3″, bringing to total amount sitting above treeline and available for transport to somewhere around 6-8″ with an average density of about 9%. Wind today will be from the NW and gusting into the mid-60mph range (95-100kph), which should be sufficient for loading to take place.

SNOWPACK: The warm spell that followed the heavy snow is setting the stage for avalanche activity. It left behind an ice crust that can act as a slippery bed surface for new wind slab to build on. When the winds shifted from the E to the NW on Thursday, they started out rather light. Expect a layer of light density snow between the crust and the denser slabs at the surface. Newly developing slabs with these conditions may feel soft and and buttery smooth underfoot, but even the small ones can be dangerous if they take you off your feet and into the rocky terrain below.

As mentioned earlier, the snowpack is in a transitional state. We are primarily concerned about the locations where bed surfaces have been developing faster. As is typical, these areas include the Lip, Center Bowl, Chute, and Left Gully in Tuckerman. In Huntington, you’ll find that Central has the largest snow surface but potential bed surfaces exist in multiple gullies. The exit snowfields in Damnation, Yale, Central, and Odell strike me as places where unstable slabs might be found. Also don’t overlook the smaller snowfields down lower in the ravine, such as on the approaches to climbs like Yale, Central, and Pinnacle.

There are some forecast areas that are not likely to be truly at Considerable danger. After the clouds clear from the mountain and we can make more accurate assessments, we may bring these areas down to “Not Posted” due to a lack of snow. Until then, we want you to recognize that hazards may exist even in smaller terrain features. Lobster Claw, Right Gully, the Lower Snowfields, and Little Headwall in Tuckerman fit this description, while in Huntington, the Escape Hatch is the leading contender for not reaching Considerable danger 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 8:40 a.m. December 13, 2014. A new advisory will be issued tomorrow.

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

2014-12-13

General Advisory for Tuckerman and Huntington Ravines

Posted 9:00a.m. Thursday, December 11, 2014. Expires at 12:00 midnight Saturday, December 13, 2014 unless updated based on a change of conditions.

This is an early season GENERAL AVALANCHE ADVISORY.  A new General Advisory will be issued if conditions warrant or within 72 hours of this release. General Advisories are issued when isolated areas of unstable snow may exist within the forecast areas. Forecasts using the 5-scale danger rating system will begin when snowfields and bed surfaces become more developed. Please remember that avalanche activity may occur before the issuance of a 5-scale danger rating forecast. As always, make your own snow stability assessments when traveling in avalanche terrain.

A large area of Low pressure sitting on the Maine coast will continue to send moisture laden air into our area. New precipitation will be wet snow or freezing rain for Thursday before transitioning to all snow Friday and into Saturday. Snow water equivalent is forecast to be in the range of a tenth to .15″ today (Thursday) which should fall as wet snow with some freezing drizzle and freezing fog mixed in.  Over the past two days, about 12″ (30cm) of snow and mixed precipitation has fallen; 10.5″ (26cm) of snow topped by wet snow and rain on Tuesday and Tuesday night, and  1.5″ (3.75cm) mixed frozen forms, rimed pellets, ice and snow (38% density) on Wednesday and Wednesday night. This mixed bag of precipitation is continuing to enlarge and connect our snow slopes and create the bed surface for new snow and wind loaded snow coming Thursday and Friday. Be prepared to assess slopes and gullies for new slabs of wet snow which may be unstable and respond to a human trigger. Some new wind loading may occur later Thursday and into Friday as winds shift to the NW and increase in velocity. Hopefully a reasonable level of visibility will allow for some visual assessment and photos today but I will at least dig in the snow to check out the snow structure and look for signs of deeper weak layers that pre-existed the larger snowfall on Tuesday-Wednesday and resulted in a human triggered, hard slab avalanche in Diagonal Gully on Monday. Currently, our best way to post photos is on the Mount Washington Avalanche Center Facebook page so seek us out, like us and look there for photos there.

Remember that the current limited snow cover can not only produce avalanches but the existing rocky terrain can beat you up in the event of a fall or being carried by an avalanche. Now is the time to carry avalanche rescue gear, be searchable by wearing your transceiver (which is turned on, right?!) and to be prepared for full winter conditions with the proper equipment, clothing and mindset.

The Sherburne Ski Trail has been getting a good bit of ski traffic though there are still some open waterbars to avoid. If you’re heading there or to the Gulf of Slides Ski Trail, remember that it is still very early in the season. Expect abrupt waterbars, hidden rocks, and plenty of exposed vegetation.

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.

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

2014-12-11 Printer friendly

Good news and bad news

As promised, we’ve been keeping our eyes on Mt. Washington in hopes that late fall would get us off to a solid start. For a while it had looked promising; reports came in of people climbing ice in both ravines. So with high hopes, I set off up the trail yesterday looking to continue preseason preparations, but mostly to wrap my head around whether or not we would need to begin issuing General Advisories before the storm that is arriving today. Here’s where the good news is separated from the bad.

Over the last couple days 11/24 & 25, the north country has been in a bit of a warm spell. Honestly, after a very long and cold winter last year, most people here were quite relieved to have this respite from the cold that had settled over the Mt. Washington Valley. My feelings were mixed. Sadly, all it took was a glance at the mountain from Pinkham Notch to know that we had lost a lot of snow and ice due to the rain and warmth of Monday and Tuesday.

View from Pinkham

It’s easy to see that a lot of snow melted without even getting out of the car.

Currently, there are only patches of snow on the ground at Hermit Lake. Looking up into Tuckerman, the north side of the ravine is completely barren of snow. The same is true for most of the Headwall. If you have your sights set on a powder feast before the turkey, I wouldn’t recommend Tuckerman due to the severe lack of snow on the ground before this upcoming event. If we wake up Thanksgiving morning with a foot of snow on the ground, undoubtedly people will try to ski the John Sherburne ski trail.  Expect many hidden hazards under this initial blanket and anticipate some dinged up bases. Ski lightly!

And the good news…our first significant winter storm is on the way! Check your favorite weather sources for the details, you won’t have a hard time finding information about this storm that’s poised to destroy the best laid Thanksgiving travel plans. The Mount Washington Observatory forecast is calling for a foot or more for the area, with some southern peaks maybe reaching two feet. We’re crossing our fingers.

This may provoke the question of why we are not yet issuing a General Advisory. If we had not gone through the recent thaw and had more well established bed surfaces, then we would not hesitate to be doing this. The chances of a slab avalanche are greatly diminished when the bed surface is as coarse and anchored as it currently is. Sure, there are small areas of water ice and even some patches of snow, so with a snowfall like this it stands to reason that these very small areas could support a small unstable slab. However, we don’t feel these are sufficient to push us into the realm of forecasting at this time. This storm  certainly has the potential to provide enough bed surface for future storms, and hopefully they’ll come soon. I do think that sluffing will be an issue if you’re out in steep terrain so recall that it doesn’t take much to knock you off your feet. So saying all this remember that there is a lack of good quality ice to climb, much of it detached, and very limited options for sliding in the ravines.  Although I’ll applaud your ambition if you try to get out I’ll be quietly questioning your judgment.

On a separate note, we’ve had some people asking if we are going to continue with the ESAW Continuing Education Series this winter. The answer is yes, and the dates and locations will be announced soon. These are free monthly sessions open to anyone with an interest in furthering their avalanche knowledge. Although I’ll be teaching the first session, the other Snow Rangers will be helping out and diversifying the presentations this season, and we may even have others from outside the Avalanche Center. I’ve yet to settle on a title, but the working idea for the December session is a review of field stability tests. We’ll look at all the popular tests, where and when each are useful, how to perform them consistently and properly, etc. If you have a burning desire to dive more deeply into a specific topic, drop me a line and let me know your idea. If it’s something we can do justice to, we might put it into the queue for future sessions.

From all of us at the Mount Washington Avalanche Center, have a Happy Thanksgiving. May this storm be the harbinger of many more this winter!

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

2014-11-25 Right Side of Tucks

The right side of Tuckerman has a tremendous amount of water running beneath the ice.

2014-11-25 Tucks Headwall

The Headwall after a couple days of thawing.

2014-11-25 Left side of Tucks

Left Gully is usually the first to fill in with snow, but it had much more than this a couple days ago.

2014-11-25 Lip and Open Book

The Lip and Open Book are classic season early ice climbs. Not this Thanksgiving weekend though.

2014-11-25 Right Gully

Right Gully with no snow.

Well it’s about time

The upcoming winter is drawing ever more near. Today I noticed that northern Maine has a Winter Storm Warning issued for 5-10″ of snow, and the NWS forecasters are discussing heavy accumulations in the mountains of northern New Hampshire, too. We’ve still got a ways to go before the season really kicks into swing, but there are some things you can be doing to get yourselves ready, such as:

  • Come to the 4th Annual Eastern Snow and Avalanche Workshop (ESAW) to refresh and engage your avalanche brain. It’s only two days away (or one if you come for the AAC social event tomorrow night). More info can be found at www.esaw.org. We still have room for more people.
  • Enroll in an avalanche course. The best dates can fill quickly. Most of the local providers can be found here on our website.
  • Enroll in a first-aid course. Sure, accidents always happen to somebody else, but why not be ready when the time comes for you to spring into action and be a hero?
  • Do a little avalanche transceiver review session. Fall leaves make for excellent opportunities to hide one and search.
  • Consider joining a “Friends” group. We have two that we work closely with, Friends of Tuckerman Ravine and Friends of the Mount Washington Avalanche Center. These two groups, as well as all the rescue groups and the Volunteer Ski Patrol, work together to help keep people safe in the mountains.
  • Get in shape! Seriously, I’m not trying to call anyone out on being slothful, but I know that for me, I have more fun when I’m feeling fit than when I feel like every step up taxes my legs and lungs to no end. And really, shouldn’t it really all just be about making everything more fun?

Keep your eyes peeled to this website as well as our Facebook page, Instagram feed, and Twitter account. We’ll be posting sporadically from now until the first General Advisory, then with some regularity until the daily advisories using the Danger Ratings Scale begin. Hopefully that time is not far off!

Jeff Lane, Snow Ranger
Mount Washington Avalanche Center