Avalanche Report for Glencoe
Avalanche Hazard Forecast
FOR PERIOD 18:00 Tue 26/04/2016 TO 18:00 Wed 27/04/2016
Forecast Snow Stability & Avalanche Hazard
Forecast Weather Influences
The provision of daily forecasts for the Glencoe area has ended for this season but a Lochaber and Northern Cairngorms forecast will be issued for next weekend on Friday 29th of April.
Key Snow Stability Observations
Observed Avalanche Hazard -
Observed Weather Influences
Observed Snow Stability and Avalanche Hazard
New snow has generally been light through this period and mostly a dusting over the summits, only one deeper accumulation fell which led to surface sloughs on steeper slopes these were recurrent for a few days. Most days gave warm spring conditions and cold nights, this helped transform and stabilised any new accumulations. Latterly, drier conditions and the cold night time temperatures have produced a stable snowpack. Cornices have and still are a hazard. New snow will arrive tomorrow.
The period has been characterised by mainly light showers, falling as snow at higher levels. Winds have been variable, often within each 24 hour period, so the resulting light accumulations of windslab have been distributed quite broadly, the common focus being the North to East aspects, where the greatest accumulations of the winters snowpack reside. The snowpack has become more moist at lower levels and has been generally diminished by the rising temperatures.
The period started with a stable spring snowpack. Over the next few days there was a little snow at higher levels, but these quantities were not large. Later in the period conditions turned a lot more spring like with mild temperature and strong sunshine having a significant affect on the snowpack on Southerly aspects. One avalanche and one significant cornice collapse occurred during this period.
The early part of this period high pressure conditions dominated the area with warm daytime temperatures, it was sunny and dry with a stable, spring snowpack. Yesterday, new snow arrived on South-Westerly winds above 700m with an increased hazard. Today, mild conditions prevailed with rain at summit level. New snow and unsettled conditions are forecast for the next 3 days with strong South-Westerly airflows this will likely lead to new windslab deposits above 800m over the Easter week-end.
The period began with milder temperatures, and precipitation as rain, moistening and destabilising the snowpack. Drier, more settled conditions followed and this led to a reduction in the avalanche hazard with the major consideration becoming wet snow instabilities due to solar warming and the increased likelihood of cornice collapse. Fine, dry settled conditions prevail at the end of the period with the Avalanche Hazard being Low.
Precipitation has fallen as snow above 600m with very light accumulations on the 4th & 6th then more snow on the 8th & 9th of March. The winds have generally been light to fresh and from most directions during the last 7 days. Temperatures have mainly been cold with overnight frosts and summit temperatures below freezing. Above 800 metres snowpack instabilities have remained during this period with NW through to SE aspects mostly affected. Mild conditions are about to take effect for next 3 days
The period began with continuing settled cold, dry conditions however after two days the wind became Southerly and the temperature rose with rain at all levels. This caused widespread wet snow instabilities. The following fall in temperature refroze the snowpack giving a stable base. Further light snow showers and shifting winds have lead to the existing distribution of localised unstable windslab deposits.
A significant thaw/freeze cycle at the weekend with heavy snowfall and strong Westerly winds resulted in large accumulations of unstable deep wind slab on many slopes, particularly N, NE, E, SE and S aspects. Since the start of this week it has been generally cold and settled which has allowed the snowpack to slowly consolidate, windslab instabilities are still present mostly on steep NE to SE slopes. Large unstable cornices still remain which are fragile.
Initially East winds deposited windslab on Westerly aspects. In the middle of the week, the wind went through a changeable spell and there was a brief spike in temperature giving wet snow instabilities. Thereafter the wind became generally South-West with snow showers building windslab on North to East aspects. The freezing level has been generally below 500 metres so snow cover has accumulated over the week leading to recent avalanche activity.
Unstable windslab has been present within the snowpack for the past week. Instabilities were on North-West through to South-East aspects above 800 metres, the avalanche category was Considerable for most days. Recently (today) the snowpack has consolidate slightly and moderately bonded windslab persists on North to South-East aspects. In the coming week ahead a drier, settled, colder spell is forecast and this will help further consolidation of the snowpack but some instabilities will exist.
Initially, heavy thaw stripped back the snowpack significantly. Two further cycles of heavy thaw and then fresh accumulations of windslab on, generally, North to East aspects followed. These fluctuations in conditions have meant the extent of snow cover has changed rapidly with little chance of overall building of the snowpack. The condition and appearance of the hills has been extremely varied, almost on a daily basis. The period is ending with a return to more wintry conditions.
Thaw conditions affected this area for the first 5 days of this period with mostly rain and strong South-Westerly winds, localised instabilities were mainly on North to East aspects. New snow arrived (Wednesday 27th & Thursday 28th) with windslab developing and present on North to East aspects above 750 metres. Fluctuating freezing levels will bring a period of significant instability with avalanche activity likely for the next 2 days then returning to colder conditions with snow.
A period again characterised by a South-Easterly airflow. Steady precipitation of snow showers mainly on West to North aspects but rising temperatures have seen the snow-line ease up. Deep snowdrifts still exist in sheltered areas in the bases of corries. The period is ending with serious thaw conditions due to heavy rain at all levels.
A period of snow showers most days and varying wind directions with falling freezing levels have added to both the depth and extent of the snow cover which now extends down to road level. In sheltered areas on many aspects there are some deep accumulations of unconsolidated snow giving the potential for the formation of further windslab deposits by wind redistribution with the next higher winds.
Unusually, the weeks weather has been dominated by a strong Easterly airflow with relatively small quantities of precipitation, falling as snow on the upper areas of the hills. The freezing level has varied between 500 - 1000 metres with no major periods of thaw. Only at the end of the period has the wind briefly turned Westerly however it is forecast to return to the East. There has been a gradual increase in the snow cover above around 750 metres but it remains generally sparce.
Roller coaster week. Christmas day recent snow on higher slopes, was followed by some moderate accumulations of new snow with drifting in the strong winds resulting in some sluffing on North-Easterly aspects, at this point general snow cover was looking quite good on higher slopes, then all change, 28th mild, 29th mild and wet, 30th very mild, very wet (storm Frank) After this event snow cover patchy in high corries and gullies, since then cold again with some new snow, windslab is developing.
24/12/15. The week started with very limited snow cover mainly restricted to the highest gullies and hollows, heavy rain and stormy conditions followed for a couple of days further depleting the cover. Some new snow fell on the 21st but was promptly striped the following day with another heavy thaw. The last couple of days have seen a return to more Wintery conditions and the outlook remains similar. There are localised instabilities where deeper windslab exists but general cover is still thin.
A period of snowfall started last Thursday night (10th December) this continued into Friday this was followed by a dry cold weekend and freezing at all levels. As the week progressed a sharp and sustained increase in temperatures and heavy rainfall quickly affected and depleted the snowpack. The snowpack has continued to thaw at all levels and is now very patchy but generally stable.
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.