All forecast areas this morning are icy and firm with low avalanche hazard. Incoming precipitation will create a widespread wind slab avalanche problem throughout our forecast terrain and increase our avalanche danger to Considerable as the day progresses. The size and tendency of avalanches to release naturally will largely depend on the amount of snow that falls this afternoon. The forecast snowfall of four to six inches of snow in the higher terrain is plenty of snow to create slabs that are capable of knocking you off your feet and carrying you down slope. Combined with an icy bed surface on our steep 35-50-degree terrain, even a small avalanche today can have serious consequences. While winds from the south might seem to target only north facing terrain for wind loading, count on cross-loading and sluffing to load east facing slopes in a similar fashion. If the steep icy base and wind loading aren’t enough of a challenge today, remember that this precipitation will be warming and becoming increasingly dense. This will create an “upside down” snowpack that may begin to act like a wet slab, making the new snow more sensitive to a human-trigger.
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At about 1:00 PM, a climber took a long sliding fall while ascending Right Gully in Tuckerman Ravine. The subject lost their footing on very hard, icy snow and was unable to self-arrest with an ice axe. The fall occurred near the top of Right Gully and the resulting high speed slide was halted below […]
The mixed bag of precipitation late yesterday and overnight largely fell as rain, freezing rain, and sleet, all of which refroze and now contribute to our hard and icy snow surface. The limited new snow mixed in this storm was heavily transported by wind, and at best amounted to quite small wind slabs that pose little danger to travelers in the alpine. Potential for a long sliding fall on our largely hard and slick snow surface should guide your terrain choices today. Realize that preventing such a fall is essential, as arresting one would be very difficult. Crampons, ice axes, and your ability to use them are essential on snow slopes. Clear skies and sun may briefly and slightly soften snow on south-facing aspects this afternoon, but this window of anything but rock-hard snow will be brief if it happens at all.
This morning, there is no avalanche problem. Avalanche terrain consists of refrozen snow that with its hard, icy surface, will require the use of crampons and an ice axe to navigate safely. Long sliding falls are currently the greatest danger. Up to 2” of snow is forecast on increasing SW wind in the afternoon and will create areas of wind slab. If we receive the upper end of the forecast snow total, areas in the lee of SW and W wind may exceed the current Low rating. Be aware of this in Hillman’s Highway, Left Gully and the Chute in Tuckerman as well as Escape Hatch, South and Odell in Huntington. Warming temperatures late may mix sleet and freezing rain into this snow, adding a wet layer to the snow surface. Travelers out late in the day should keep an eye on the sky and be prepared to re-evaluate plans if we receive the upper end of forecast totals.
Huntington and Tuckerman Ravines have LOW avalanche danger. All forecast areas have Low avalanche danger. Generally safe avalanche conditions exist. The Little Headwall is not rated and is once again an open waterfall with very little snow coverage remaining. AVALANCHE PROBLEM: Avalanche concerns today have been erased by the record setting warmth and rain over […]
Our primary problem will be in the form of the skier or rider initiated loose wet avalanches which are trending towards likely today. Loose Wet avalanches which will be possible for a skier or snowboarder to initiate in steep terrain are our primary avalanche problem. Moderate rated areas held more soft snow at the surface prior to the current warm and wet weather and will be capable of producing large loose wet sluff and point release avalanches. While such avalanches would likely not bury you without a significant terrain trap, they can easily cause a fall and even carry you downhill. Realize that the steep terrain where loose wet activity is most likely to occur is also a particularly high consequence place to take a fall.
If you venture into the terrain today, be aware that the record warmth is awakening a number of our typical spring hazards. Water flowing beneath the snow surface is creating areas of undermined snow that you could easily break through. Overhead hazards including icefall and to a lesser extent rockfall should be respected. When choosing terrain today, remember that these avoidable hazards have resulted in many accidents, some of them fatal. Don’t neglect to look at safer and equally rewarding options.
Wet Slab is our primary avalanche problem with small slabs in many areas and large slabs in specific areas decreasing in stability through the day. Rain and melt water should wet recently formed wind slabs and percolate to the robust crust beneath them, lubricating this bed surface for avalanches to run on. Moderate rated areas hold significantly less new wind slab and are instead dominated by an old melt/freeze crust snow surface that is again melting. Wet slab avalanches are unlikely in anything but the recently formed wind slab. Peak instability of wet slabs is difficult to predict, but we expect human triggered avalanches to become likely and natural avalanches possible at some point later today. Wet Loose avalanches will be a rising concern as well today and could occur in much of our terrain. If in our terrain today, be on the lookout for overhead hazards in the form of icefall, rockfall, and of course the wet slab avalanches mentioned above. Also watch for weak snow undermined by water running beneath it which you could break through.
Wind slab that formed over the weekend sits on a firm bed surface that has gone through multiple melt-freeze cycles. Yesterday’s 5” of snow fell on increasing wind speeds, creating large areas of wind slab. Wind speeds were at times strong enough to scour areas down to the icy bed surface, though these tend to be in lower portions of our terrain and present themselves with the appearance of gray snow or may even have a reflective sheen with today’s sun. Areas with a northerly and southerly exposure have the most scouring down low and contain firm-looking sastrugi up high, including Damnation and North in Huntington as well as the looker’s left fork of Hillman’s Highway. Places of most concern today will be the Sluice through Chute in Tuckerman and Central and Pinnacle in Huntington. Smooth wind slab dominates these areas and has covered rocks and old crown lines that were visible on Friday, giving an indication to the amount of loading that took place yesterday. Current blowing snow on SW wind of 45 mph is a sign that wind transport has not ended and our fetch still has transportable snow. SW shifting W wind today will allow areas of wind slab to grow in size today. While many gullies have old surface down low due to wind scouring, mid-elevations contain the largest smooth-looking wind slab that could prove touchy to human-triggers today.
Wind Slabs that will continue to develop through the day are our primary avalanche problem. Avalanche danger will increase through this afternoon as wind builds our several inches of new snow into much thicker slabs. Increasing wind speeds mean than snow deposited will be generally more dense over less dense snow and therefore be increasingly sensitive to a trigger. Natural avalanches will be possible and human triggered avalanches will be likely. Dry loose sluffs which could knock you off your feet, initiated naturally or by a human, should also be on your radar in our steep terrain. We still have relatively thin snow coverage in much of our terrain, particularly Huntington Ravine. This means that many hazards in the runout of our avalanche paths elevate the consequences of even a small avalanche. Consider the rocks, vegetation, and terrain traps which may be below you if you choose to travel in avalanche terrain today. Also remember that though avalanches typically occur on slopes steeper than 30 degrees, they can run well into flat areas like the floor of Tuckerman Ravine.
Huntington Ravine has MODERATE and LOW avalanche danger. Central and Pinnacle Gullies have Moderate avalanche danger. Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully to identify features of concern. All other forecast areas have Low avalanche danger. Watch for unstable snow on isolated terrain features. Tuckerman Ravine has MODERATE and LOW […]
Huntington and Tuckerman Ravine have LOW avalanche danger. All forecast areas have Low avalanche danger. Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features. AVALANCHE PROBLEM: The warm spell yesterday and last night brought another period of settlement and melt. The snowpack has already been through above freezing temperatures earlier in the […]
Strategic Field Observations CT22 Q1 SC, ECTP27, PST 60/100 End, no whumphing, some shooting cracks, I see wind blowing snow around, I have to push kinda hard to make a hand shear fail… What does this all mean? CAN I SKI IT? We have these stability assessment tools and many more at our disposal. They’re […]
Huntington Ravine and Tuckerman Ravines have LOW avalanche danger. Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features. AVALANCHE PROBLEM: No significant avalanche problem exists today as our dry spell continues. Surface snow consists of refrozen rain soaked crust which is hard and strong enough to not only support your weight but […]
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.
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.
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INCIDENTS & ACCIDENTS
The Mount Washington Avalanche Center is a partnership between the White Mountain National Forest, White Mountain Avalanche Education Foundation and Friends of Tuckerman Ravine and other community organizations. The avalanche forecast applies only to backcountry areas, not operating ski areas, and describes general avalanche conditions which vary locally. The avalanche information provided is the sole responsibility of the USDA Forest Service.