Avalanche Forecast Archives

2017 – 2018 Season

Avalanche Advisory for Wednesday, February 14, 2018

Date: February 14, 2018
The Ravines hold a predominantly hard refrozen snow surface. Today’s weather could allow some softening on south facing aspects but only for a brief window if at all. Cloud cover will likely keep solar heating and softening of surface snow to a minimum. Therefore, we don’t expect wet loose sluff avalanches to be an issue today. Ice and rock fall could be an issue even with slight warming and should be on your radar as potential overhead hazards. That said, long sliding fall potential on our hard icy snow pack likely remains your greatest hazard. Rocks and other obstacles are exposed below many steep areas, particularly in Huntington Ravine. Be sure that your crampon and ice axe skills are strong if choosing to climb steep snow slopes today.

Avalanche Advisory for Tuesday, February 13, 2018

Date: February 13, 2018
The melt and subsequent refreeze of our surface snow in the past 3 days has dramatically increased stability in our snowpack. You’ll find a mixed bag of surface conditions from breakable crust to dense and supportable refrozen snow. Most if not all of our snow in steep terrain will easily allow a long sliding fall. Rocks, vegetation, and other hazards could be in the path of such a fall. Our terrain does have better snow coverage than late January, but it’s still thin. Be on your game with crampons, ice axe, and alpine travel skills if you’re hoping to climb steep snow today.

Avalanche Advisory for Monday, February 12, 2018

Date: February 12, 2018
Our upper snowpack is currently refreezing following the recent above freezing temperatures and wet precipitation. Around Hermit Lake, the crust forming is currently one inch thick and breakable. Prior to the warm conditions which began midday Saturday, our surface snow was a mix of soft and hard wind slab with scattered areas of exposed January melt-freeze crust. Stability concerns of these layers are becoming minimal with the refreeze. These varied surface conditions will reflect today in the form of a crust that will likely be breakable in previously soft areas and supportable in previously hard areas. Expect a mixed bag of travel techniques to be necessary. Long sliding falls should be on your mind today; consider breaking your rope for third and fourth class terrain. Realize that areas with a crust breakable under your boots might easily support the weight of a sliding human body.

Avalanche Advisory for Sunday, February 11, 2018

Date: February 11, 2018
Huntington Ravine has CONSIDERABLE and MODERATE avalanche danger. Central and Pinnacle gullies have Considerable avalanche danger. Dangerous avalanche conditions. Careful snowpack evaluation, cautious route finding, and conservative decision making are essential. All other forecast areas have Moderate avalanche danger. Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully to identify features of […]

Avalanche Advisory for Saturday, February 10, 2018

Date: February 10, 2018
Today, new snow, wind slabs and natural releases of dry loose snow will strain the snowpack and the weak layer beneath. High rated areas hold the greatest potential for a large avalanche due to the thicker wind slabs in place before today’s snowfall. Considerable rated areas hold similar concerns, though avalanches in these areas are likely to be a bit smaller or less likely to fail naturally due terrain configuration or a lower angle. No matter the rating, you’ll need to bring your A game to this tournament if you want to make it to the next round.

Avalanche Advisory for Friday, February 9, 2018

Date: February 9, 2018
Today’s avalanche problem is wind slab. This developed Wednesday night into Thursday and has naturally released in a few steep, wind loaded areas. Continued cold weather today will not improve stability. Areas of the greatest concern are larger wind loading slopes in the lee of W and WNW wind, such as Central Gully, the Sluice and Chute, places that received significant loading but have not avalanched. Avalanche activity yesterday below the ice in the Lip to the Center Bowl and the area beneath Harvard Bulge and Yale failed on the interface between old wind slab or ice crust and the new snow. This natural activity should serve as a red flag for areas that still contain areas of wind slab and no signs of avalanche activity. Evaluate snow carefully before you commit to a slope.

Avalanche Advisory for Wednesday, January 31, 2018

Date: January 31, 2018
The dominant feature of the snowpack remains the widespread knife hard, ice glazed surface. Crampons are necessary to climb beyond low angle terrain due to this slick, hard surface. Stability tests and travel in Left Gully to the choke, about ¾ of the way up, last weekend showed that the older wind slab was well bonded to this icy surface. Nearer the surface, firmer (1F) wind slab over the thicker 4F slab created a clean shear at the interface between these two layers but neither layer showed any desire to propagate a crack much beyond your feet. No avalanche activity has been reported in these wind slabs. Elsewhere, the firm snow provides for quick and efficient cramponing but is an unforgivingly fast surface if you stumble so stay vigilant!

Avalanche Advisory for Tuesday, January 30, 2018

Date: January 30, 2018
Huntington Ravine has LOW avalanche danger. All forecast areas have Low avalanche danger. Watch for unstable snow on isolated terrain features. Tuckerman Ravine has LOW avalanche danger. All forecast areas have Low avalanche danger. Watch for unstable snow on isolated terrain features. The Little Headwall is not rated due to a lack of snow.  The Lip still […]

Avalanche Advisory for Monday, January 29, 2018

Date: January 29, 2018
Huntington Ravine has LOW avalanche danger. All forecast areas have Low avalanche danger. Watch for unstable snow on isolated terrain features. Tuckerman Ravine has LOW avalanche danger. All forecast areas have Low avalanche danger. Watch for unstable snow on isolated terrain features. Little Headwall has not refrozen completely and is far from filled in with […]

Avalanche Advisory for January 28, 2018

Date: January 28, 2018
New wind slab may develop today if the mountain receives the upper end of forecast snowfall of a trace to two inches. The new snow could add stress to the scattered wind slabs that already exist in the terrain due to the inch or so that fell last night in higher terrain and blew into our forecast zones. Wind slabs scattered through these lee, sheltered areas may become sensitive to human triggering if the new snow forms more slabs on them. Yesterday, wind slabs showed no tendency to propagate a crack but additional snow load on top could make them more susceptible to human triggers. Evaluate snow carefully as you find your way through the terrain today.

Avalanche Advisory for Saturday, January 27, 2018

Date: January 27, 2018
Huntington Ravine has LOW avalanche danger. All forecast areas have Low avalanche danger. Watch for unstable snow on isolated terrain features. Tuckerman Ravine has MODERATE and LOW avalanche danger. Sluice, Lip, Center Bowl, Chute and Left Gully have Moderate avalanche danger. Heightened avalanche conditions exist on specific terrain features. Evaluate snow and terrain carefully. All […]

Avalanche Advisory for Friday, January 26, 2018

Date: January 26, 2018
The mountain received 2.5” of snow at the tail end of Tuesday’s low pressure system followed by strong winds from the west then north-west. Wind velocity was strong enough to scour the Alpine Garden above the ravines and deposit wind slab in our areas of concern. By and large, in good visibility, these wind slabs should not be difficult to avoid. In steep narrow gullies where route options are limited, venturing onto and triggering one of these slabs could result in a very nasty sliding fall on the icy bed surface. In the upper reaches of Left Gully and Chute, wind slab stretches wall to wall with no real option to avoid them. These wind slabs were poorly bonded to the ice crust beneath and sheared cleanly and easily. Be aware that low rated areas in our terrain may also be harboring these problematic wind slabs, though smaller in size with more options to avoid them altogether.   

Avalanche Advisory for Thursday, January 25, 2018

Date: January 25, 2018
Huntington Ravine has LOW avalanche danger. All forecast areas have Low avalanche danger. Watch for unstable snow on isolated terrain features. Tuckerman Ravine has MODERATE and LOW avalanche danger. Lip, Center Bowl, Chute and Left Gully have Moderate avalanche danger. Heightened avalanche conditions exist on specific terrain features. Evaluate snow and terrain carefully. All other […]

Avalanche Advisory for Wednesday, January 24, 2018

Date: January 24, 2018
Areas of wind slab exist in Moderate rated forecast zones. Though small, these slabs are likely to be unstable enough to be triggered by a person traveling on them. Due to the small amount of snow which fell overnight, the size and distribution of these slabs is limited. Low rated areas contain isolated areas of wind slab and will likely receive more scouring and less deposition of new snow. Continued snow shower activity early today may contribute more snow to areas of instability. All of our terrain contains an abundance of stout, icy rain crust which creates a dangerous slide-for-life hazard. Unfortunately, avoiding the wind slabs puts you onto this hard crust. The most imminent threat that will remain constant for the next few days is the icy crust and the potential for a long sliding fall into rocks, stout bushes and holes melted into the snowpack. The Lip contains an unusually nasty fall potential due to the 20’ crown face in the middle of the run and in the fall line of the Tuckerman Ravine Trail.

Avalanche Advisory for Tuesday, January 23, 2018

Date: January 23, 2018
The relatively small wind slabs built since late last week will become wet slabs as significant rainfall occurs today. Remember that triggering a small avalanche in consequential terrain can still have dire consequences. That said, natural and human triggered avalanches are unlikely today. The exception to these small slabs is “hang fire” in the area of the large avalanche crown in the Lip. Your primary concern in this location should be moisture and warm temperatures today that will decrease stability in the unsupported snow above the crown, which is currently a vertical wall of snow up to 20’ in height. Cautious travelers will avoid terrain under the Lip today for the high consequence of a large though unlikely avalanche from above this crown line.

Avalanche Advisory for Monday, January 22, 2018

Date: January 22, 2018
Winter weather is inbound though the small amount of snowfall forecast today has minimal potential to elevate our avalanche danger. More isolated pockets of wind slab may develop from new snow on moderate winds today and tonight remain our primary avalanche problem. Small in size, if triggered these slabs aren’t likely to bury you but could cause a long sliding fall on our largely rock hard snow surface. Until more significant accumulation of snow and mixed precipitation late tonight and into tomorrow, sliding falls above numerous hazards remain a primary concern for travelers in steep terrain.

Avalanche Advisory for Sunday, January 21, 2018

Date: January 21, 2018
Isolated pockets of wind slab exist in our terrain, though much of the snow surface is very hard and refrozen following the warm-up that occurred late last week. This very hard, icy snow will likely be your primary travel concern today for its potential to allow a long sliding fall. If you did trigger a small wind slab avalanche, it could easily knock you off your feet and cause such a fall. Realize that even those who are highly skilled in steep snow climbing with crampons and ice axe would have little chance of effectively self-arresting to stop this kind of slide. Additionally, melt out of rocks, trees, stream beds, and other hazards in the fall line of steep terrain make a traumatic outcome of a long sliding fall likely.

Avalanche Advisory for Saturday, January 20, 2018

Date: January 20, 2018
Huntington and Tuckerman Ravines have LOW avalanche danger. Natural and human-triggered avalanches are unlikely in all forecast areas.  Watch for unstable snow on isolated terrain features.  The Little Headwall is mostly open water or frozen waterfall ice. Due to the open waterfall hole and 20’ crown line, the Tuckerman Ravine Trail is closed in the […]

Avalanche Advisory for Friday, January 19, 2018

Date: January 19, 2018
New snow earlier this week struggled to stick to the hard refrozen surface as it was transported by wind. Pockets of new wind slab do exist but are largely small and avoidable. If you’ve tried to dig in our snow lately, you’ve noticed that the hard surface snow is tough to penetrate with any tool. Instability will be limited to snow above this refrozen layer for the foreseeable future. We’ve said it already today and have all week, but we continue to stress the hardness of the refrozen snow surface. It provides good purchase for crampons but is smooth enough to easily accelerate a small fall to a slide for life in steep terrain. You would be hard pressed to arrest such a fall.

Avalanche Advisory for Thursday, January 18, 2018

Date: January 18, 2018
Wind slab may develop today when gusty winds blow available snow into avalanche terrain. Limited amounts of new snow in the past 48 hours, along with moderate winds should limit wind slab development but stay tuned in to what’s happening at the ridge tops. As of this writing, upper start zones are mostly old surface with new snow generally pushed down to midslope through wind action or sluffing. Human triggering of these wind slabs is possible today though the resulting avalanche would be on the smaller side. Of equal or greater concern to avalanche issues today is the slide-for-life conditions camouflaged by the thin blanket of new snow. Any stumble or fall is likely to have serious consequences in any steep terrain due to the hard surface. Roping up early and not falling are your best protection on steep slopes.

Avalanche Advisory for Wednesday, January 17, 2018

Date: January 17, 2018
Both avalanche types are developing on top of a hard, icy crust that will be not only a slippery bed surface but will also create slide-for-life conditions. Due to the light snowfall today, the size and distribution of these avalanche types will grow through the day and depend on receiving the forecast amount of snow. The most imminent threat that will remain constant throughout the day is the icy crust and the potential for a long sliding fall into rocks, stout bushes and holes melted into the snowpack.

Avalanche Advisory for Tuesday, January 16, 2018

Date: January 16, 2018
A thick layer of hard refrozen snow encapsulates our remaining snowpack. Thickness of this layer varies spatially with the degree to which recent rain saturated the upper snowpack, but seems to be at least a few inches to over a foot. Needless to say, this is a supportable crust in the alpine and requires good crampon and ice axe skills to travel in steep terrain. Snow today should not accumulate enough to warrant new stability issues with potential to harm a person. This could change tomorrow following more snowfall. As discussed above, other mountain hazards are quite relevant today. Though disappointing for snow lovers, the weather of the past week illustrated the mountain’s ability to produce extraordinary avalanche events, as evidenced by Friday’s massive wet snow avalanche. It’s an important reminder of the power of snow on a steep slope.

Avalanche Advisory for Monday, January 15, 2018

Date: January 15, 2018
The strong temperature swing Saturday that followed our significant rainstorm resulted in hard refrozen surface snow and generally stable conditions throughout our snowpack. As mentioned above, this means full on slide for life conditions in our steep terrain. Snow depth and coverage has decreased significantly. North, Damnation, Yale, South, and Escape Hatch gullies in Huntington Ravine do not hold continuous top to bottom snow. The same is of course true for the open stream that is the Little Headwall. Snow in other areas has become quite narrow, and the tops of a number of gullies have melted to rock. In Tuckerman, Right Gully was hit particularly hard while other areas faired reasonably well and continue to hold top to bottom snow. It’s a drastic shift from the plentiful dry snow of early last week and from the conditions which produced Friday’s massive wet avalanche in the Lip of Tuckerman Ravine.

Avalanche Advisory for Sunday, January 14, 2018

Date: January 14, 2018
A solid refreeze of our heavily wetted snowpack has greatly increased stability which will hold through this forecast period. Natural and human triggered avalanches are unlikely at best. If you’re in our terrain today, a number of other hazards should make avalanches a lesser concern.

Avalanche Advisory Saturday, January 13, 2018

Date: January 13, 2018
Wet Slab and Wet Loose avalanches will continue to be our primary avalanche problem until our snowpack solidly refreezes later today or tonight. Peak instability, with possible natural avalanches and likely human triggered avalanches, may have already passed since this warm and wet storm started early yesterday. That said, the nearly 1” or rain in the past 6 hours could be causing continued instability. Temperatures that are currently dropping will allow our avalanche danger to decrease significantly through the day. If rain switches to snow early and pushes the higher end of forecast snow accumulation, we could see areas of new snow instability develop by the end of the day, though other hazards like undermined snow and firm snow conditions will likely be of greater concern.

Avalanche Advisory for Friday, January 12, 2018

Date: January 12, 2018
Wet slab avalanches may slide naturally without a human trigger today. As rain and warm temperatures continue to reach deeper into the snowpack, the likelihood and size of an avalanche will increase. While relatively slow moving, this avalanche type is particularly dense and potentially destructive. The floor of Tuckerman Ravine is particularly threatened by a natural avalanche from the Headwall area.

Additionally, higher volume watercourses such as the main waterfall in the Lip as well as Central and Pinnacle Gullies in Huntington, among other streams, will undermine snow and create fall or drowning hazards. It is likely that the main waterfall/Open Book area will open up today along with the Little Headwall stream course. Both of these areas have been the scene of serious or fatal accidents.

Avalanche Advisory for Sunday, December 31, 2017

Date: December 31, 2017
Variability in our upper snowpack keeps ratings at Moderate for much of the terrain today, with wind slab continuing as our primary concern. We expect greatest instability in the smooth slabs commonly existing between ½ and ¾ of the way up much of our terrain. Our upper start zones are largely wind hammered to a firm and textured snow surface which would be hard pressed to produce an avalanche. Thin areas of the softest and smoothest pockets of wind slab have the greatest potential to produce a human triggered avalanche today. Low rated areas will tend to offer more options to avoid today’s avalanche problem. Don’t become complacent due to firm feeling snow. Dig and probe before committing to travel on wind slabs.

Avalanche Advisory for Saturday, December 30, 2017

Date: December 30, 2017
Firm and generally stubborn wind slabs are the primary avalanche problem today. These firm slabs will have good bridging strength in lots of areas but realize that thin spots, convexities and other trigger points may still be lurking.  Evaluate snow and terrain carefully as you move around the terrain today. Recent avalanche activity in much of our terrain has swept out the ice crust built from the rain event last weekend but lower angled areas which didn’t avalanche may still hold this potentially problematic layer. You’ll find firm (1F) but mostly smooth slabs in most of our terrain that hasn’t seen the scouring or sastrugi building action of the wind near the ridgetops. Low rated areas have fewer areas of concern and provide more terrain opportunities to avoid them.

Avalanche Advisory for Friday, December 29, 2017

Date: December 29, 2017
Firm and relatively stubborn to trigger wind slabs that exist over much of our terrain are our primary avalanche problem today. Realize that this layer will be easiest to trigger in thinner and/or softer areas, which is difficult to visually discern when route finding. Today remains a low probability, high consequence risk situation for a number of reasons. Bitterly cold weather will complicate any problem and a number of our avalanche paths continue to have nasty runouts. Continue to realistically consider “what if” scenarios in your travel planning.

Avalanche Advisory for Thursday, December 28, 2017

Date: December 28, 2017
This advisory expires at Midnight. Huntington and Tuckerman Ravine have MODERATE avalanche danger. Natural avalanches are unlikely and human-triggered avalanches are possible in all forecast areas. Evaluate snow and terrain carefully. Lower Snowfields and Little Headwall in Tuckerman have Low avalanche danger due to lack of a developed snowpack. Watch for unstable snow on isolated […]