Avalanche Report for Glencoe
Avalanche Hazard Forecast
FOR PERIOD 18:00 Fri 13/11/2015 TO 18:00 Sat 14/11/2015
Forecasted Snow Stability & Avalanche Hazard
Usually, snow depth is thin and lies on bare ground. However, in many wind sheltered places, snow carried by the wind can form deeper isolated accumulations, here instabilities can be expected with the possibility of human triggered avalanches. Deposits will generally be small pockets located high in corrie back walls, around corrie rims and in other wind sheltered locations.
Forecasted Weather Influences
General Advice We recommend that mountain goers venturing into the hills continue to observe weather forecasts prior to their excursions, and visual observations of conditions during their trip. This information is important in making good plans and allowing for flexible decision making. Early winter snowfalls can produce a cover of snow on all aspects and at most levels in the Scottish Mountains. Fluctuating freezing levels will improve stability and snow accumulations may disappear.
Observed Avalanche Hazard -
Observed Weather Influences
Observed Snow Stability and Avalanche Hazard
Last weekend new snow and wintry conditions arrived down to 400m, new windslab development took place and the avalanche hazard increased. A heavy thaw on Tuesday, where rain saturated the snowpack at all elevations this consolidated most instabilities in the snowpack. Colder temperatures returned on Wednesday stabilising the moist snowpack at all elevations. Now, warmer conditions have softened the snowpack surface at most levels. Snowpack stability is generally good with settled conditions .
It has been a settled week, no precipitation only the odd spit of rain and the freezing level has remained above the summits through this period. The snowpack is now spring snow which is generally stable. Due to high temperatures and the amount of solar radiation, localised wet snow instabilities exist on steep North-East through to East-South aspects. All cornices have become unstable and prone to collapse. The avalanche hazard has been Moderate through the period and often a localised hazard.
Winter returned at the start of the week with a fair bit of snow at higher levels but the rain wasn't far behind as it came on heavy by the start of the weekend. This was then followed by several days of fairly heavy fresh snow and stormy conditions culminating in today which has been calm dry and clear for much of the day. There now exist a fairly extensive snow cover on many of the hills in the Glencoe area. Much of the snow is bone hard and is very unforgiving in the event of a simple slip
It was mostly another dry and settled week with some pleasant spring sunshine at times. The freezing level has been fluctuating, and generally the snowpack has been quite stable. There was a little fresh snow on Monday night but the quantities were not large. A significant change in the weather occurred on Thursday with significant fresh snow at high levels. This fresh windslab was poorly bonded, and natural avalanche may well have occurred, but poor visibility prevented any being observed.
The past week has generally been dry, no new snow has materialised and the snowpack has generally been well bonded and in a consolidated state. The Avalanche hazard has been 'Localised Moderate' or 'Moderate' whenever new snow was forecast. Some localised instabilities still exist on North through East to South-East aspects mainly above 900 metres. No significant snowfall is forecast.
In generally it has been a very stormy week. The start of the week was also very very wet. Cornice collapse and wet snow avalanche activity was recorded in Coire an Lochan on both Friday and Saturday. There was some fresh snow on Sunday and Monday, but quantities were not extensive, and these deposits soon consolidated in the fluctuating temperatures. Despite the rain and mild conditions there is still good snow-cover at higher levels.
The period commenced with snow showers on South-West and Westerly winds down to around 400 metres. On Sunday night more persistent snow and strong Westerly winds affected all levels, with similar conditions on Monday/Tuesday. This storm snow resulted in deep drifts forming in many sheltered areas even down to lower levels with scouring on the windward slopes. Wednesday turned out dry calm and settled with a return to mild moist and windy conditions today.
The period has seen the progressive build up over six days of windslab accumulations on North-West through North-East to South-East aspects. There was evidence during this time of natural slab avalanches on Easterly aspects above 900 metres. This was followed by an abrupt overnight thaw after which debris from a number of wet slab releases was observed. The period ended with a return to cold weather, which has refrozen the snowpack, and the accumulation of some fresh windslab deposits.
The period began with a continuation of the relatively settled weather - generally dry with the snowpack gradually consolidating and becoming more stable. The second half of the period was characterised by more unsettled weather with considerable accumulations of fresh unstable windslab forming. This was followed by thaw conditions which moistened and softened the snowpack occasioning some cornice collapse but no major slab releases. Falling temperatures are now stabilising the snowpack.
12/02/2015 The week has been dry apart from the odd snow flurry and some drizzle. Freezing levels have been complex with temperature inversions for much of the time where general freezing levels were above the summits with a fluctuating sub zero band lying below. This has given some great atmospheric hill days where visibility existed mainly on the hills at the Eastern end of the glen. The snowpack today is firm and icy. There not been a significant reduction in snow cover throughout the period.
The period has been characterised by Northerly winds and low temperatures, with the freezing level mainly between 200 - 300 metres. This has resulted in windslab accumulations mainly on North-East through South to South-West aspects and other slopes being mainly scoured and stable. There was some redistribution of the snowpack by changes in the wind direction but accumulations were generally light. The period has ended with a rise in the temperature which will start to consolidate the snowpack.
Fluctuating conditions with three significant thaw periods have caused the snowpack to go through a series of melt/freeze cycles resulting in a diminished and stable snowpack towards the end of the period. Further snowfall at all levels has produced fresh windslab on this firm base.
The area had significant snow fall at the early part of this period, the Avalanche hazard then increase to High. The snowpack settled slightly but areas of weakly bonded windslab remained on North to South-East aspects. Colder, clear conditions with light winds then prevailed, during the last 3 days, winds have shifted to South-Easterly but it has remained dry, some light redistribution has taken place. The avalanche hazard has been Considerable from the 16th January to date.
The period started with a thaw which diminished the snow pack and produced wet snow instabilities. The subsequent fall in temperature consolidated the snowpack and this thaw/ freeze cycle was repeated. It then became considerably colder and the end of the period has been characterised by heavier snowfall accompanied by hail which has lead to widespread unstable conditions higher up, and snow at road level.
The weather during the last seven days has been dominated by a couple of large thaws with cooler but drier periods in-between. The snowpack is not extensive,with the main accumulations being on North to East aspects above 800 metres. The amounts of snow which has arrived between the thaws has been been quite small, and these deposits have tended to consolidate quite rapidly in variable weather. No avalanches were recorded in the area during the week.
The period started with cold conditions with some fresh snow and wind redistribution of the snowpack creating windslab on mainly Eastern aspects. As the temperature started to rise and it became increasingly rainy, wet snow instabilities were produced in the existing deposits of windslab as the snowpack became increasingly moist and soft. The temperature at the end of the period is starting to fall and the snowpack will be consolidating.
After some fresh snow last Friday and Saturday, there was a major thaw on Sunday. Heavy rain and summit temperature of plus five degrees had a significant affect on the snowpack. From Monday it slowly turned colder, the existing snowpack froze, and there were further windslab deposits. The majority of the snowpack lies on North through East to South-East aspects above 700metres. The avalanche hazard category was considerable for most of the time. No avalanches were recorded during the period.
The first week of the season has been mostly been cold with snow showers. There was a brief thaw on Saturday night and then a more significant one through Wednesday and Thursday. Winds have been consistantly from between the South-West and North-West, and so windward aspects hold little snow, particularly after the thaw. Significant deposits, which have now generally stabilised, exist on lee ascents. A couple of relatively small avalanches were reported, one triggered and the other natural.
The snowpack has been mainly isothermic and moist at most levels for the past week and is generally well bonded and stable. We have encountered South, South-West and Westesterly weather influences with the freezing level generally above the summits. The avalanche hazard has been Low for 6 of the days with one day with a localised Moderate hazard. The day Moderate (localised) was forecast did not materialize because new snow amounts were not significant. This is the last summary of the 2013/2014
The snowpack has been isothermic and moist at most levels for the past week and is generally well bonded and stable. We have encountered Easterly weather influences with the freezing level generally above the summits. The avalanche hazard has been Low for 6 of the days with one day with a localised Moderate hazard.
Wintery conditions returned last Friday 21 March with a fair amount of new snow over the next two days mainly above 800 metres. Victim triggered avalanches were recorded on Sunday. Windy conditions followed with strong to gale South-Easterlies affecting the area. Natural avalanches were recorded on East and North West slopes. On Tuesday a return to milder conditions saw rain affecting all levels. Wednesday was dry and mild and Thursday colder with snow showers and Easterly winds.
Its been a stormy week with unsettled mild weather on most days. Rain has fallen at all levels until today when snow fell above 700m. During the week the snowpack has been moist with wet snow instabilities on steep slopes, no avalanche have been recorded. At present, the new accumulations of snow and windslab are not to depth and mostly on North to East aspect and give a localised Considereable hazard. More snow is forecast for the next few days with the freezing level around 600-800 metres.
The period started with mild weather leading to wet snow instabilities. As temperatures fell stability of the snowpack generally improved. Levels of precipitation were low and there was some fine sunny weather which produced some instabilities on South facing slopes. The temperature rising with some rain increased the avalanche risk at the end of the period. Cornice collapse remained a serious issue throughout the period.
The week has been challenging for snowpack stability there have been many avalanches this week at least 12 recorded. The avalanche category was generally Considerable with avalanches are likely and the last 2 days have had a High category and again avalanches did happen. The snow was generally dry for the first part of the week but now it is moist especially at lower levels.
Another stormy week with a fair amount of new snow on the higher slopes on most days apart from 23rd which was wet at all levels. Snow quantities in the Glencoe area remain exceptionally high on the upper slopes. Winds have mainly been from a South-East through South to Westerly direction.
The stormy conditions have continued. Winds have been strong with snowfall occurring most days which has continued to build up large areas of windslab and bury huts and lifts in the ski area. There has been some avalanche activity recorded, most notably a large natural avalanche out of Great Gully on Buachaille Etive Mor on Sunday night. It is likely there has been a lot of avalanches which have not been recorded due to the poor visibility.
There has been extensive and deep snow cover above 600m all week. Strong SE winds during the first part of this period continued to deposit unstable windslab on SW through W and N to NE aspects mainly above 700m, with natural and triggered avalanches recorded on Thursday and Sunday. From Sunday onwards mainly strong winds varied between SE and SW depositing windslab mainly on W through N to E aspects above 750m.
There is an extensive and very deep cover of snow above 700 metres with strangely very little, if any accumulations in the glens. Over the last week winds have been predominantly from the South, then South East, very strong at times. This has lead to a significant build up of windslab in many sheltered gullies and South West through North to North East aspects. With continuing colder temperatures, many of these areas remain unstable.
Temperature fluctuations at the start of this period consolidated the existing snowpack. Fresh windslab was then deposited mainly on W to N to NE aspects above 800m, with winds that varied between SE and SW. Over Wednesday night and during Thursday there was significant snowfall with strong SSW to WNW winds which deposited deep accumulations of fresh unstable windslab, mainly on NW through N and E to SE aspects above 750m.
At first winds were mainly South-Westerly and windslab formed primarily on North to East aspects above 800m. Then from Sunday winds became Southerly or South-Easterly and windslab was present on West through North to East aspects above 800m. During Wednesday the freezing level rose above the summits and in the late afternoon and early evening heavy rain fell at all levels. On Thursday the freezing level dropped to around 900m and the snowpack started to refreeze and consolidate.
Above 800 metres there is an extensive cover of snow on North-Westerly through North to South-Easterly aspects. A recent melt -freeze cycle has rendered much of the older snowpack firm and stable. Some areas of fresh windslab are forming in sheltered locations such as gully exits and steep Northerly and Easterly aspects. Below 700 metres the snow cover is much depleted due to milder conditions and rain.
Significant accumulations of snow are still present on most aspects especially above 650 metres. The snowpack stability has varied during the past 7 days it started off being very unstable and has now become almost isothermic. Changeable unsettled weather is forecast for the next few days with more snowfall which will produce more instabilities. The greatest accumulations are mainly on W to N to SE aspects above 750m.
Stormy conditions over the last few days added a deep cover of snow on North-West through North to Easterly aspects initially down to lower levels. Many windward slopes are fairly clear of any significant cover. Outlook is milder on Friday then frequent snow showers on Saturday.
Significant accumulations of snow compared to last week. Winter snowpack developing on mainly NW to N to SE aspects above 750m. Immediate concerns (Thursday 19 Dec) are rising temperatures in the forecast period combined with new snow instability on above noted aspects and elevations.
Limited snowpack with patches mainly on North through East to South-East aspects above 850m.