Avalanche Forecast Archives

2016 – 2017 Season

Avalanche Advisory for Sunday, April 9, 2017

Date: April 9, 2017
This advisory expires at Midnight. Huntington Ravine has MODERATE and LOW avalanche danger. North, Damnation, Yale and Central Gully have Moderate avalanche danger. Natural avalanches are unlikely and human-triggered avalanches are possible. All other forecast areas have Low avalanche danger. Natural and human triggered avalanches are unlikely.  Tuckerman Ravine has CONSIDERABLE and MODERATE avalanche danger. […]

Avalanche Advisory for Saturday, April 8, 2017

Date: April 8, 2017
The 4-5” of new snow which fell overnight on strong winds, combined with 2-4” more snow today will make human-triggered wind slab avalanches likely throughout our forecast area. Natural avalanches are also possible and can run the full length of our well-developed slide paths. An avalanche occurring today in the Lip or Center Bowl area in Tuckerman Ravine could run into the buried trees and shrubs which mark the entrance to the floor of the Ravine. Smaller avalanches in cross loaded slopes will also be problem. Low visibility, new snow and continued wind-loading are all the redflags you should need to develop your travel plans this morning. Today is a good day to go to the rock gym or perhaps take a windy, low visibility hike to the summit. Winter is holding on for another day.

Avalanche Advisory for Friday, April 7, 2017

Date: April 7, 2017
The snowpack at forecast area elevations will gain strength today as cooler temperatures allow it to freeze. Around ¾” of rain saturated most our snowpack last night resulting in widespread large rollerballs and loose wet avalanche activity. Until the refreeze takes hold of surface snow today, the possibility of small human-triggered, loose wet avalanches will remain. Moderate rated areas have a greater chance of releasing a larger wet slab avalanche from a skier or rider, or their sluff. These wet avalanche problems will be replaced by more wintry problems later. Lingering moisture will begin to fall as snow, creating the possibility of scattered areas of wind slab forming in lee areas of the southwest wind. Due to the low rate of snowfall combined with limited available snow on the ground, these wind slabs should be limited in size and distribution through the terrain until later this afternoon and tonight when wind shifts to the northwest. Anticipate wind slab avalanche danger to increase around dark and into the night as 2-4 inches more snow falls on a wind speed and direction capable of loading lee forecast areas.

AVALANCHE ADVISORY FOR THURSDAY, APRIL 6, 2017

Date: April 6, 2017
This advisory expires at Midnight. Tuckerman and Huntington Ravines have MODERATE avalanche danger today. Natural avalanches are unlikely and human triggered avalanches are possible. Evaluate snow and terrain carefully. The only exception to this rating is the Little Headwall which has Low avalanche danger, with natural and human triggered avalanches being unlikely. Open water exists […]

Avalanche Advisory for Wednesday, April 5, 2017

Date: April 5, 2017
Storm slab, from the 10” of dense, new snow recorded on the summit in the past 24 hours, and wind slab, due to cross-loading and direct loading of some terrain features, will make human triggered avalanches likely this morning in steep terrain. Snow, ice pellets and some freezing drizzle overnight created an “upside down”, or increasingly dense snowpack, due to warming temperatures. Last night’s precipitation will add to instabilities that were observed yesterday afternoon when test slopes were propagating cracks. In the steepest terrain today, any new precipitation especially combined with warm morning temperatures, will make the wind slabs and storm slabs unstable, creating dangerous avalanche conditions. Dense fog will reduce visibility and make safe travel options and visual assessment challenging.

Avalanche Advisory for Tuesday, April 4, 2017

Date: April 4, 2017
Today, Wind Slab will form on north and east-facing aspects. This hazard will increase through the day as snowfall accumulates and wind speed increases. While north-facing slopes will see the greatest amount of loading due to being directly in the lee of wind, east-facing slopes contain the largest snowfields and have the potential to produce the largest avalanche. While south-facing slopes will see little loading, today’s snow will become denser creating an upside down snowpack that could become reactive to human triggers. While several slopes avalanched over the weekend, many did not. The potential for wind slab today stepping down into the slab that formed over the weekend is possible. Be aware of the possibility of avalanches becoming large today.

Avalanche Advisory for Monday, April 3, 2017

Date: April 3, 2017
Wet slab and wet loose avalanches will create unstable conditions as heating resumes today. The upper snowpack (10-20cm) of south facing aspects were heated by the sun yesterday and refroze overnight, creating low avalanche danger this morning. Cold, dry snow remains below that melt/freeze crust which will heat up rapidly today due warm air temperatures and clear skies. Slopes with an east and south facing aspect will heat to the point that a wet loose sluff, or skier or climber, could trigger a larger wet slab avalanche. Areas of wind slab that developed Saturday night, and to a lesser extent last night, will become unstable due to this heating. Unlike the human-triggered, soft wind slabs over the weekend, today’s avalanches could break further upslope above you, making them more likely to capture and carry you. Old or new tracks on a slope today do not mean that the slope won’t avalanche.

Avalanche Advisory for Sunday, April 2, 2017

Date: April 2, 2017
This advisory expires at Midnight. Huntington and Tuckerman Ravines have CONSIDERABLE avalanche danger. Natural avalanches are possible and human-triggered avalanches are likely. Dangerous avalanches conditions will exist today. Careful snowpack and weather evaluation, cautious route finding and conservative decision making are essential. The only exception to this rating is the Little Headwall, which has LOW […]

Avalanche Advisory for April 1, 2017

Date: April 1, 2017
Storm slab avalanches may propagate a crack and avalanche today with a human trigger due to increasing cohesion within the new snow from warming temperatures. Though wind is generally light, especially by Mount Washington standards, recent gusts from the east in the 40 mph range on the summit will contribute to this slab formation. In addition to the storm and wind slab problems, significant sluffing will occur both naturally and as a skiers or riders push snow around. Due to the high density of the new snow, these sluffs could entrain a lot of snow. Today is a really good day to consider the nature of your runout. Think about terrain traps, trees, boulders or cliffs in your fall line and stick to lower angled slopes. The Little Headwall area contain a couple of open holes to the stream below.

Avalanche Advisory for Friday, March 31, 2017

Date: March 31, 2017
A low pressure system passing to the south will bring up to an inch of water to the area with the majority of this falling tonight and tomorrow. Low wind speeds from the southeast and 2” of snow will keep avalanche danger low today with natural and human-triggered avalanches unlikely in all areas. Avalanche danger will continue to rise through the weekend so anticipate elevated danger through Sunday, when winds from the northwest load snow into our forecast area.

Avalanche Advisory for Thursday, March 30, 2017

Date: March 30, 2017
Huntington Ravine and Tuckerman Ravine have LOW avalanche danger. Natural and human-triggered avalanches are unlikely. Watch for unstable snow on isolated terrain features. AVALANCHE PROBLEM: The wind slab avalanche problem today will present less hazard management problems than the hard, icy refrozen rain crust beneath. Rain on Monday and Tuesday followed by nearly 24 hours […]

Avalanche Advisory for Wednesday, March 29, 2017

Date: March 29, 2017
Current weather has removed the threat of wet avalanches. Saturated snow from warm and freezing rain will be subjected to cold temperatures today and turn to an impenetrable snowpack. This will create a slick sliding surface that will necessitate the use of crampons and an ice axe for safe travel. With up to 2” of snow possible this afternoon on rapidly increasing NW winds, wind slab may develop in areas. This will likely be isolated behind terrain features due to strong wind and a hard snow surface.

Avalanche Advisory for Tuesday, March 28, 2017

Date: March 28, 2017
The avalanche problem today will be wet slab. The hazard will increase today slowly due to temperatures remaining only just above freezing and cloud cover remaining in place. With minimal precipitation forecast today, the hazard will lie largely in meltwater lubricating a layer within the snowpack rather than a rapid additional load. The greatest hazard for the day will be in places where the wet slab is the thickest, such as the Lip or Central Gully, as these areas have the potential to produce larger avalanches than other forecast areas. As wet slabs act as liquid concrete once they release, bear in mind that even a thin wet slab can push people into potentially hazardous terrain.

Avalanche Advisory for Monday, March 27, 2017

Date: March 27, 2017
Today, wind slab will be stressed by additional precipitation and will possibly become saturated, creating wet slab and wet loose avalanche problems. The hazard will increase through the day as the amount of precipitation and temperature increases. This avalanche problem is notorious for its unpredictability and today will be no exception. Looking at the amount of water arriving today, it will likely be at most half an inch by midnight. This is not a huge amount of liquid and combined with the ambient air temperature, may not be enough to overwhelm the cohesiveness of the slab. The areas of greatest concern today are rated Considerable due to the larger possible size of an avalanche as well as the steepness of the slope. Moderate rated areas could have similar but smaller avalanches that could be equally dangerous depending on the terrain.

Avalanche Advisory for Sunday, March 26, 2017

Date: March 26, 2017
Today’s avalanche problem will be driven by heating of the snow by sunshine and warm temperatures. Areas with the most soft wind slabs like Sluice and Lip in Tuckerman Ravine and Central in Huntington have the greatest potential to produce a human-triggered avalanche. As sun warms the snow this morning, the soft snow will become heavy, begin to saturate with water and produce loose wet sluffs and possibly wet slabs large enough to push you around. Today’s warming is not extreme enough to create large wet slabs but skiing will become challenging in the variable “mashed potato” snow and firmer old crust. Areas of old, hard icy snow in Tucks are not widespread but can be found in Left Gully and low in the Chute. This icy surface is generally discontinuous and will create some travel challenges going up or down. Hillman’s Highway has a mix of firmer slabs and softer slabs so expect heavier snow there as well as things heat up.

Avalanche Advisory for Saturday, March 25, 2017

Date: March 25, 2017
Wind slabs formed from 7” of new snow on west winds in the past 24 hours keeps the likelihood of human-triggered avalanches in the considerable range. Wind velocities were ideal for loading slopes with an east facing aspect. These slabs are likely to be soft enough to be sensitive to a human-trigger and may be large enough to carry you downhill and possibly bury. Though the threat of natural avalanches is by and large past, the likelihood of human-triggered avalanches makes careful evaluation of snowpack, cautious route-finding and conservative decision making essential. Dense summit fog is currently hampering our ability to make observations so consider each avalanche path to be loaded and waiting for a trigger until you confirm otherwise. Forecast areas with a moderate rating are solidly in that range so assess snow and terrain carefully. A disparity in recorded snowfall between the summit and our forecast elevations gives us some uncertainty about the size of potential avalanches today but this shouldn’t change you travel precautions in avalanche terrain.

Avalanche Advisory for Friday, March 24, 2017

Date: March 24, 2017
We are starting out the day with human triggered avalanches being possible only in the steepest portions of Sluice, Lip and Center Bowl, and possibly Central Gully in Huntington, with human-triggered avalanches being unlikely in all other forecast areas due to the strength or lack of continuity of existing wind slabs. East facing forecast areas, particularly upper start zones, will be in the bullseye for developing these wind slabs this afternoon while other aspects will become crossloaded. New snow on increasing west winds will add a bit of stress to existing wind slabs, but the primary problem will be within the new snow. Increasing temperatures and increasing wind speeds will set the stage for increasingly dense slabs over soft new snow falling later this morning. As the day wears on, small to medium sized natural avalanches will become possible in considerable rated terrain. Moderate rated terrain could generate smaller human triggered avalanches and even some small, loose dry natural avalanches in the steepest areas. Reduced visibility and increasing hazard will make conservative terrain choices a good idea today.

Avalanche Advisory for Thursday, March 23, 2017

Date: March 23, 2017
Wind slabs remain the primary avalanche problem. Low rated areas are a mix of scoured old surface with areas of heavily wind sculpted and eroded sastrugi snow. You may encounter unstable snow in isolated areas but options to travel on the stable, icy old surface will be plentiful in low rated areas. Stubborn and firm wind slabs may provide easier travel but will also harbor a low probability risk of triggering a stubborn, hard wind slab. Moderate rated areas contain much more smooth wind slab. This typically means that the area was dominated by deposition throughout the wind and snow event. Anticipate firm, continuous thicker slabs in these areas that will also be stubborn and fairly strong but with weaker layers of new snow beneath that bring a higher probability of fracture and failure. As is often the case, these slabs have good bridging power but the possibility of finding and triggering a thin spot in the slab remains. In general, our moderate rated areas are at the lower end of the moderate rating while low rated areas are nudging towards moderate unless you are on the icy, old surface.

Avalanche Advisory for Wednesday, March 22, 2017

Date: March 22, 2017
This advisory expires at Midnight. Huntington and Tuckerman Ravine have CONSIDERABLE and MODERATE avalanche danger. In Tuckerman, Sluice, Lip, Center Bowl, and Chute have Considerable avalanche danger. Central, Pinnacle, and Odell Gullies in Huntington Ravine have Considerable avalanche danger. Natural avalanches are possible and human-triggered avalanches are likely. Dangerous avalanche conditions exist. Careful snowpack evaluation, […]

Avalanche Advisory for Tuesday, March 21, 2017

Date: March 21, 2017
This morning, areas of hard wind slab will be encountered on north facing aspects. East and south facing slopes received sun and warmth yesterday that refroze last night and should present more of a long sliding fall hazard than avalanche problem this morning. Snow showers through the day may bring up to 2” of new snow with increasing W and NW wind. Pockets of wind slab will develop, particularly in sheltered areas of westerly wind, creating and increasing avalanche hazard as the day progresses. These pockets will likely be isolated due to the small amount of incoming snow and soft due to lighter wind speeds.

Avalanche Advisory for Monday, March 20, 2017

Date: March 20, 2017
Our primary avalanche problem today will be caused by the breakdown of strength in existing wind slabs due to heating of the snow. These firm slabs have been strong enough to bridge over soft weak layers beneath and resist failure but today’s heating will be the first real test since their formation. Today’s ratings are based on slope aspect as well as the size and continuity of the slabs. Lobster Claw and Right Gully along with North Gully in Huntington have much less snow in them or have already seen heating during yesterday’s mid-day warmth. As a result, those slopes are less likely to avalanche due to a human-trigger than nearby slopes with a moderate rating. When you begin to sink in to your boot tops or when it becomes easy to make a snowball on a steep slope, it will be time to reevaluate whether you should be travelling in that terrain.

Avalanche Advisory for Sunday, March 19, 2017

Date: March 19, 2017
Wind slab remains our avalanche problem today. Primarily formed Wednesday night and Thursday, this firm slab exists over much of our terrain, is largest in Sluice, Lip, and Center Bowl, and can be found in pockets of varying size on most aspects. Bonds between this layer and the underlying snow surface have gained strength over the past several days. While resistant to a human trigger, the resulting avalanche could be large. This possibility, albeit unlikely, certainly remains and demands respect in your travel decisions.

Avalanche Advisory for Saturday, March 18, 2017

Date: March 18, 2017
It’s still winter up here! The recent Nor’easter, followed by a significant wind event, has maintained a dynamic snowpack in the ravines. A strong and supportable rain crust formed several weeks ago is present in the snowpack in essentially all of our terrain. Moderate winds from nearly every direction during and after the Nor’easter created a layering of varied density wind slabs, much of which were subsequently wiped out by stronger West to Northwest winds Wednesday night and Thursday. Areas lee of these winds, particularly Center Bowl, Lip, and Sluice, hold a firm, pencil to one finger hardness wind slab of varied thickness from an inch to several feet. Other areas hold pockets of a similarly deposited snow. These slabs will be stubborn to trigger and offer fairly good conditions for travel, still demanding cautious travel practices. The old rain crust is the primary surface where this recently deposited snow does not exist. This crust is quite stable but is smooth and icy and would easily allow a long sliding fall.

Avalanche Advisory for Friday, March 17, 2017

Date: March 17, 2017
Densely packed, wind transported snow has built wind slab over a softer layer of loose snow over the past 48 hours. Due to the potential size of these slabs and the challenges posed by avoiding them, they are the primary avalanche problem in moderate rated areas today. While these slabs may propagate a crack, the strength of the firm slab above makes these slabs very stubborn. This type of wind slab is most concentrated in areas in the lee of a northwest wind such as just beneath the ice in Center Bowl, below the rollover in the Lip and high in Chute. Central Gully appears to have an area of this firm slab, as well. In addition to the primary firm, wind slab problem, softer pockets of wind slab exist here and there in both Ravines but are much smaller and discontinuous so shouldn’t pose too much of a challenge to avoid. Hillman’s and Left Gully are on the low end of the moderate rating due to more areas being scoured. Evaluate snow and terrain carefully today.

Avalanche Advisory for Thursday, March 16, 2017

Date: March 16, 2017
This advisory expires at Midnight. Huntington Ravine and Tuckerman Ravine have CONSIDERABLE avalanche danger. Natural avalanches are possible and human-triggered avalanches are likely. Dangerous avalanche conditions exist. The only exception to this rating is Little Headwall which has Low avalanche danger. A combination of small wind slabs, ice bulges and open water exist there. AVALANCHE […]

Avalanche Advisory for Wednesday, March 15, 2017

Date: March 15, 2017
This advisory expires at Midnight.   Huntington Ravine has CONSIDERABLE and MODERATE avalanche danger. Central, Pinnacle, Odell, South and Escape Hatch have Considerable avalanche danger. Natural avalanches are possible and human-triggered avalanches are likely. Danger avalanche conditions exist. Careful snowpack evaluation, cautious route-finding, and conservative decision-making are essential. North, Damnation, and Yale Gully have Moderate […]

Avalanche Advisory for Tuesday, March 14, 2017

Date: March 14, 2017
The incoming Nor’easter will create Wind Slab in avalanche terrain. Wind direction will dictate where this problem forms and to what degree loading happens with increasing hazard through the day. Light south winds this morning will load north-facing slopes during the morning. As the wind shifts to the east and increases in speed, north-facing as well as south-facing slopes will see cross-loading. While our forecast areas do not include slopes with a western aspect, west-facing slopes outside of our forecast area will see significant wind loading as the wind shifts to the east. As the wind direction continues its move toward the north, south-facing slopes will see the most loading with cross-loading finally bringing snow to east-facing slopes. As this shift to the N and NW takes place, areas in Tuckerman and Huntington Ravine may exceed the Considerable rating after this advisory expires at midnight.

Avalanche Advisory for Monday, March 13, 2017

Date: March 13, 2017
Wind Slab is creating the avalanche hazard today. Today, the danger will remain constant as the forecast weather will not have an impact on the areas of concern or the snowpack as a whole. The largest wind slab in our terrain currently sits just under the rollover of the Tuckerman Headwall with the largest pocket existing in the Lip. This can be identified from afar by its smooth appearance and cleanness when compared to the dirty looking, textured old surface. This old surface is firm and will create the potential for long, sliding falls, something to keep in mind when moving around the mountain.

Avalanche Advisory for Sunday, March 12, 2017

Date: March 12, 2017
Firm Wind Slab developed from Friday’s snow and strong WNW winds on Saturday. Today, continued wind loading on decreasing winds will deposit remaining snow available for transport onto these areas, but should not be enough to increase the hazard for the day. Slopes in lee areas of WNW winds have the largest pockets of wind slab. These are identifiable by a smooth appearance and cleaner looking snow when compared next to the gray, refrozen old surface. In Tuckerman, Sluice through the Chute have pockets that connect these forecast areas, creating the potential for a larger avalanche when compared to pockets in Low rated areas.

Avalanche Advisory for Saturday, March 11, 2017

Date: March 11, 2017
New wind slabs which formed overnight, and which will continue to form through the day, will create dangerous avalanche conditions in the floor of Tuckerman Ravine as well as higher in avalanche paths. Other forecast areas with a Moderate danger rating will have heightened avalanche conditions and will require careful snow and terrain evaluation. Wind, blowing snow and cold temperatures will reduce visibility and make group communication challenging so conservative decision making is advised in all forecast areas.