Avalanche Forecast Archives

2016 – 2017 Season

Avalanche Advisory for Friday, March 10, 2017

Date: March 10, 2017
Wind slabs that developed yesterday will be the primary avalanche problem for the first half of the day with danger ratings at the lower end of those written above. Snow squall activity along with steadier upslope precipitation this afternoon will drive these ratings up and make human-triggered avalanches possible in all forecast areas. Avalanche paths, like Lip and Center Bowl as well as Central and Pinnacle Gully, that are in the lee of west winds, will reach maximum instability towards evening as winds reach prime loading velocities. The size of potential avalanches will depend on the amount of snow produced by the combined upslope snow showers along with a Norlun trough. Expect potential wind slabs this morning to be on the smaller side in moderate rated areas but grow to medium sized avalanches capable of burying a person by nightfall if we receive the upper end of the 3-5” forecast by the MWObs. Wind speed and direction are prime to create touchy wind slabs which could propagate easily. Evaluate snow, weather and terrain carefully today.

Avalanche Advisory for Thursday, March 9, 2017

Date: March 9, 2017
This advisory expires at Midnight. Huntington Ravine has MODERATE and LOW avalanche danger. Central Gully has 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. Watch for unstable snow on isolated terrain features.  Tuckerman Ravine has MODERATE and […]

Avalanche Advisory for Wednesday, March 8, 2017

Date: March 8, 2017
Rain and warm temperatures created a wet slab problem this morning. Wet slabs will be found today in areas that contained wind slab over the past few days, largely in the Lip and Center Bowl with scattered pockets elsewhere. This avalanche problem is hard to predict and can be caused by quickly adding weight to the slab or by meltwater lubricating a sliding surface within the snowpack. With rainfall diminishing and temperatures dropping, the likelihood of wet avalanches will diminish due to the snowpack refreezing. Later in the day, a fast moving system may bring periods of heavy snow and up to 3” total. Increasing wind from the west has the potential to turn this snow into wind slab. If we receive the upper end of the forecast snow total, the avalanche hazard rating may exceed the current Low rating and require careful snow and terrain evaluation for safe travel.

Avalanche Advisory for Tuesday, March 7, 2017

Date: March 7, 2017
The avalanche problem today will change as the day progresses, from wind slab this morning to wet slab tonight. Two inches (2”) of snow overnight combined with up to another inch this morning on 30 mph SW winds will deposit isolated pockets of wind slab near the start zones of our forecast areas. These will be larger in gullies with N or E aspects like Central, Odell, South, Left and Hillman’s Highway, but as these displayed the largest amounts of scouring during this past weekend, the contrast between this newly deposited snow and the old hard surface will make safe travel possible. As precipitation changes to rain this evening, these newly formed wind slabs as well as the wind slab that formed over the weekend will turn to wet slab. As the rain adds weight to the slabs, stability will decrease, with the greatest period of instability occurring after this advisory expires at midnight.

Avalanche Advisory for Monday, March 6, 2017

Date: March 6, 2017
Sunshine and warming temperatures will decrease the stability of existing wind slabs. These slabs are limited in distribution through our forecast areas with the largest of them in the Lip in Tuckerman, and to a lesser extent, low in Central Gully beneath the ice bulge in Huntington. These wind slabs were stubborn yesterday but are medium to large sized and potentially dangerous in the Lip and Center Bowl area. Smaller pockets of wind slab will weaken sooner and could pose a problem in steep terrain in other low rated forecast areas. Be wary of any of these wind slabs on east and south facing aspects today and do some stability tests or hand shears before committing to the slope. Old refrozen gray surfaces will present more stable travel options, though carry a greater risk of long sliding falls, especially on shady aspects. The snowpack is starting out quite cold so the timing of warming and associated softening of the snow is uncertain.

Avalanche Advisory for Sunday, March 5, 2017

Date: March 5, 2017
igns of natural avalanche activity occurring last night due to wind loading of the scant amount of snow that has fallen the past couple of days has raised concerns for human-triggered avalanches today. With the exception of the Lip and right side of Center Bowl, most of these wind slabs will be on the smaller side. Look for smooth areas of snow that will contrast easily with nearby old, gray snow or new, wind eroded sastrugi snow. Test these wind slabs for signs of instability before committing to the slope. The larger fetch upwind of Tuckerman made more snow available for larger wind slabs to develop in the Lip with pockets in Sluice and Center Bowl. Central Gully in Huntington also has pockets of wind slab that are bordering on the Moderate danger rating while most of the rest of the gullies are scoured.

Avalanche Advisory for Saturday, March 4, 2017

Date: March 4, 2017
Just over three inches (3”) of snow arrived over the past 48 hours on strong west winds, creating firm wind slab in areas of our terrain. This clean new snow will be easy to identify over the dirty, refrozen old surface. The largest pockets will be found just under the rollover of Tuckerman with scattered, smaller pockets in the lee areas of NW winds. With an inch of snow possible today, the wind slab may grow in size, but will not affect the stability of the snowpack. Many areas, including most of Huntington Ravine, are scoured down to old surface. What remains is a very icy textured surface. Any slip or fall today will accelerate quickly so be aware of this when moving around the mountain.

Avalanche Advisory for Friday, March 3, 2017

Date: March 3, 2017
This advisory expires at Midnight. Huntington and Tuckerman Ravines have LOW avalanche danger. All forecast areas have Low avalanche danger. Natural and human-triggered avalanches are unlikely. The Little Headwall is not forecast due to lack of snow. Skiing or riding from the Bowl is challenging now.  AVALANCHE PROBLEM: High west and northwest winds transported yesterday’s […]

Avalanche Advisory for Thursday, March 2, 2017

Date: March 2, 2017
Lingering moisture in the atmosphere is bringing moderate snowfall to Hermit Lake this morning. This snow is likely to bond well to the old snow surface but weather changes today will create suspect layers in this new snow. Currently, high west winds are transporting snow into lee terrain. This wind will increase and shift to the northwest today, continuing to load mid-slope start zones and cross load others. Anticipate elevated danger from new wind slabs today especially if we meet or exceed the forecast snowfall totals.

Avalanche Advisory for Wednesday, March 1, 2017

Date: March 1, 2017
With the temperature warming and rain falling, Wet Slabs will be the main problem today. These will develop as the wind slab that formed Sunday is saturated with rain and melting snow. The largest pockets of this are just under the rollover in the Bowl in Tuckerman and can also be found in sheltered areas of terrain features in other locations... The rest of the snowpack spent much of last week above freezing and should handle the water today with no real problems.

Avalanche Advisory for Tuesday, February 28, 2017

Date: February 28, 2017
This advisory expires at Midnight. Huntington Ravine and Tuckerman Ravine 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 no longer forecast this season as it is now an open river. AVALANCHE PROBLEM: The avalanche problem today will be […]

Avalanche Advisory for Monday, February 27, 2017

Date: February 27, 2017
This advisory expires at Midnight.  Huntington Ravine and Tuckerman Ravine have LOW avalanche danger. Natural and human-triggered avalanches are unlikely. The Little Headwall has returned to being a waterfall.  AVALANCHE PROBLEM: Night before last, 2” or so of new snow created thin wind slabs in lee terrain. An inch or so of new snow may […]

Avalanche Advisory for Sunday, February 26, 2017

Date: February 26, 2017
This advisory expires at midnight. Huntington Ravine and Tuckerman Ravine have LOW avalanche danger. Natural and human-triggered avalanches are unlikely in all forecast areas. Watch for unstable snow on isolated terrain features. AVALANCHE PROBLEM: Wind Slab will form today from snow showers last night as well as likely continued upslope snowfall today. The hazard will increase […]

Avalanche Advisory for Saturday, February 25, 2017

Date: February 25, 2017
Our snowpack has been warming for over 72 hours. Springtime hazards are emerging and will likely play a larger role than the avalanche hazard today. Pay particular attention to icefall, glide cracks and undermined snow.

Avalanche Advisory for Friday, February 24, 2017

Date: February 24, 2017
Skier triggered wet-loose avalanches will be the primary avalanche problem today though other emerging spring hazards will pose an equal or greater danger. Loose but heavy sluffs of snow kicked up by a skier can be challenging to deal with at times so be mindful of this hazard, especially if venturing into areas with a sunny aspect or an area that’s not been ridden recently. Though the prolonged heat wave has generally allowed weaker layers in our snowpack to settle and bond, wet slab avalanches are a greater possibility today as water travels deeper into the snowpack. The Lip waterfall often flows onto an ice layer within the snowpack resulting in a wet slab avalanche during early spring thaws with rain. Today’s record warmth and rain in the afternoon will increase the potential for this sort of avalanche activity in our forecast area.

Avalanche Advisory for February 23, 2017

Date: February 23, 2017
Skier triggered wet-loose avalanches will be the primary avalanche problem today though other emerging spring hazards will pose an equal or greater danger. Loose but heavy sluffs of snow kicked up by a skier can be challenging to deal with at times so be mindful of this hazard, especially if venturing into areas with a sunny aspect or a previously unskied area. Several warm days have allowed our snow to adapt to the heating through settlement of the layers of snow, making a deeper wet slab avalanche only a very remote possibility.

Avalanche Advisory for Wednesday, February 22, 2017

Date: February 22, 2017
As the day progresses, the chance of a human-triggered wind slab will decrease as the snowpack warms, however this will increase the chances of a wet slab. Pockets of wind slab are isolated and are identifiable by their smooth appearance; they are primarily in the steeper terrain and in lee areas of NW winds. Areas of greatest concern for a wet slab today would be areas that have not seen much traffic and will bear the brunt of the sunshine today. The Sluice fits this category well and also has the added objective hazard of icefall potential today. With warming temperatures, it doesn’t have to be spring to have springtime hazards.

Avalanche Advisory for Tuesday, February 21, 2017

Date: February 21, 2017
Pockets of Wind Slab exist in our terrain and will provide the primary avalanche problem for the day. These pockets can be identified by their smooth appearance and are found in lee areas of NW winds. The likelihood of triggering these pockets is small and will decrease further through the day as settlement occurs. With clear skies and ample sunshine today, south facing aspects will soften and may present the problems with loose wet sluff management. This sluff can act like concrete, slow moving and hard to escape once entrained in it. Worth keeping in mind is the large wind slab that formed after our latest avalanche cycle last week. It will likely take more than a human to trigger this slab. The potential trigger out there today could be icefall. With temperatures warming, this possibility should be discussed.

Avalanche Advisory for Monday, February 20, 2017

Date: February 20, 2017
Our snow pack has refrozen on southern aspect which had seen some softening over the weekend. After prolonged NW winds in the 50-80 mph range, some snow was still being transported into our start zones in a limited way yesterday afternoon. Around a half inch of new snow added to the total amount available last night. Small pockets of soft wind slab will be the primary avalanche problem. Reloaded lee areas in the Sluice through Chute area following our last avalanche cycle is the area of most concern for larger, lingering wind slab. Though unlikely to be triggered by a skier or climber due to the strength and bridging power of these slabs, this would be larger than the pockets of new soft wind slab on the surface.

Avalanche Advisory for Sunday, February 19, 2017

Date: February 19, 2017
Today, the avalanche problem will differ depending on the slope aspect. The likeliest hazard today will be Wet Loose avalanches. These will remain a threat until the snowpack refreezes tonight. Slopes of most concern for wet loose will be S and SE facing slopes such as Lobster Claw, Right Gully, and Sluice. Other slopes may have the potential for wet loose depending on how long temperatures remain warm. Wet Slabs may come into play today if the warm temperatures penetrate deep enough into the snowpack or if thinner slabs are encountered. Again, this is most likely on S facing slopes. Areas that remained in the shade yesterday and have more recently started to warm still harbor characteristics of Wind Slab. While less likely that these would be triggered by a human than a wet loose slide, the size and destructiveness of a wind slab avalanche today would be far greater.

Avalanche Advisory for Saturday, February 18, 2017

Date: February 18, 2017
Wind slabs that developed over the past 48 hours will be the primary stability concern today. These will be firm and stubborn in most areas.  Beware of smooth areas of wind slab in the steepest areas or in any convex area you might find. Though these wind slabs will be tough to trigger, it is not too much of a reach to imagine someone finding the right thin spot in steep terrain. While an active avalanche cycle ripped out the soft weak failure layer in most of our larger forecast areas, most slopes have not yet been tested by climbers or skiers so don’t forget to dig and poke around when entering the terrain.

Avalanche Advisory for Saturday, February 18, 2017

Date: February 18, 2017
Wind slabs that developed over the past 48 hours will be the primary stability concern today. These will be firm and stubborn in most areas. Beware of smooth areas of wind slab in the steepest areas or in any convex area you might find. Though these wind slabs will be tough to trigger, it is not too much of a reach to imagine someone finding the right thin spot in steep terrain. While an active avalanche cycle ripped out the soft weak failure layer in most of our larger forecast areas, most slopes have not yet been tested by climbers or skiers so don’t forget to dig and poke around when entering the terrain.

Avalanche Advisory for Friday, February 17, 2017

Date: February 17, 2017
This advisory expires at Midnight. Huntington Ravine has MODERATE avalanche danger today. All forecast areas in Huntington Ravine have Moderate avalanche danger. Natural avalanches are unlikely and human-triggered avalanches are possible. Heightened avalanche conditions exist on specific terrain features. Evaluate snow and terrain carefully to identify features concern. Tuckerman Ravine has CONSIDERABLE and MODERATE avalanche […]

Avalanche Advisory for Thursday, February 16, 2017

Date: February 16, 2017
This morning, there is Considerable danger of Wind Slab and Dry Loose avalanches from 8” of new snow last night. Though this new snow was deposited on generally light winds, some gusty conditions mid-storm may have created a cohesive slab in some areas. Much larger and more dangerous Wind Slab avalanches will be likely this afternoon as wind from the northwest ramps up. These slabs will release naturally and most likely run far into flat areas like the floor of Tuckerman Ravine and the wooded areas in Huntington. Our avalanche paths have grown very large in the past week. The size of these slopes, the available new snow, and the high winds have set the stage for very dangerous avalanche conditions today. Travel in avalanche terrain is not recommended.

Avalanche Advisory for Wednesday, February 15, 2017

Date: February 15, 2017
This advisory expires at Midnight.   All forecast areas of Huntington and Tuckerman Ravine have CONSIDERABLE avalanche danger. Natural avalanches are possible and human-triggered avalanches are likely. Dangerous avalanche conditions exist. Careful snowpack evaluation, cautious route-finding and conservative decision-making are essential today. The only exception to this is the Little Headwall which has Low avalanche […]

Avalanche Advisory for Tuesday, February 14, 2017

Date: February 14, 2017
Wind and a barrage of snow over the past 36 hours formed Wind Slab in our terrain. The weather today will not increase the avalanche danger. The area of greatest concern today will be the Sluice through Chute in Tuckerman. A fresh crown in the Lip is a sign that this area is on the edge of shedding its most recent layer of wind slab and may be reactive to a human-trigger. All other forecast areas are displaying sign of avalanche debris with few crown lines visible. This should highlight the reloading that has taken place with several avalanche cycles occurring yesterday.

Avalanche Advisory for Monday, February 13, 2017

Date: February 13, 2017
This morning, there is Considerable danger of Storm Slab avalanches from 17” of new snow last night. Diminishing wind speeds at the start of the storm deposited this snow in our entire forecast area with little wind effect. Steep terrain this morning also has significant Loose Dry avalanche potential with Wind Slab concerns in upper start zones. As wind ramps up from the north, rapid loading of slopes with a southern through eastern aspect will occur and build large and dangerous wind slabs. These slabs will release naturally and most likely run far into flat areas like the floor of Tuckerman Ravine and the Fan in Huntington, as well as through avalanche paths in adjacent areas like the Gulf of Slides.

Avalanche Advisory for Sunday, February 12, 2017

Date: February 12, 2017
This advisory expires at Midnight. Huntington and Tuckerman Ravine have MODERATE avalanche danger today. All forecast areas have Moderate avalanche danger. Natural avalanches are unlikely and human-triggered avalanches are possible. Heightened avalanche conditions exist on specific terrain features. Evaluate snow and terrain carefully to identify features of concern. The only exception to this rating is […]

Avalanche Advisory for Saturday, February 11, 2017

Date: February 11, 2017
Small, loose dry natural avalanches could occur in a few areas like Pinnacle Gully and Chute. The primary concern however will be the wind slab avalanches that will likely be easy to trigger due to the low density snow coupled with light winds. Look for these wind slabs in upper start zones in the lee of features sheltered from southwest wind. Terrain with a north facing component is likely to have the greatest wind slab problem so be particularly heads up in Hillman’s Highway, Left Gully, South and Odell Gullies.

Avalanche Advisory for Friday, February 10, 2017

Date: February 10, 2017
This advisory expires at Midnight. Huntington Ravine has MODERATE and LOW avalanche danger today. Central, Pinnacle, Odell, South and Escape Hatch have Moderate avalanche danger. Natural avalanches are unlikely and human-triggered avalanches are possible. North, Damnation and Yale have Low avalanche danger. Natural and human-triggered avalanches are unlikely. Tuckerman Ravine has MODERATE and LOW avalanche […]