firefly

Well summarised, spindrift. Your reasons for persistence of the snow are all accurate, and they are all very important. I'm visiting the snow at Aonach Beag (not Aonach Mor) this weekend, and will report back. For those who are interested I did an interview that appeared on the Grand Tours of Scotland programme on Friday. http://www.bbc.co.uk/programmes/b01n8v0c My section is at 6:40. Ignore the awful 'climate expert' comment (I am most certainly not)!

The snow to which you refer, PM, actually lasted for a total of 14 days. The four days you refer to (28-31 August 2011) were only part of the story. Such was the extent of the drifting from the NW that the snow persisted into the second week of September on Ben Macdui. Astonishing for snow falling in August. Normally it is ephemeral. A very good example of the continued cool weather is demonstrated in Stuart Gordon's picture from yesterday, showing fresh snow on Braeriach. http://www.winterhighland.info/forum/file.php?2,file=8379 The eagle-eyed amongst you will spot the old snow in the picture: Sphinx and Pinnacles.

Yes, and the Cairngorms too. The trend has been cool weather for the last 4 weeks or so, and I would imagine little in the way of significant melting of the remaining snow. Couple this with the additional snow that has fallen and it's a promising picture.

Another update for all you chionophiles! Saturday saw myself and Mark Atkinson take to the hills of the Cairngorms in search of the two most permanent snow patches in the British Isles. Garbh Choire Mor of Braeriach, as many of you will know by now, holds two patches named Sphinx and Pinnacles. These patches have disappeared on 5 times in the last 100 odd years. Last year it was a close-run thing, but this year looks much, much better. To get to this location, the most isolated part of the Cairngorms, is not at all easy. Whichever way one approaches by, it's a minimum of about 12 miles round trip, and amongst very difficult terrain. However, the reward is all the more satisfying because of this. General view from below The Pinnacles patch was 35 metres long, and approximately 4-5 metres deep at its deepest. There was a layer of fresh snow on both patches, as you can see by its 'Daz white' look. The more observant amongst you will see the fresh sugar coating of snow on the cliffs behind. Pinnacles in the foreground, with Sphinx at the back Mark at Pinnacles Bergschrund Sphinx patch was not as long, though quite a bit deeper overall. The total length was 24.8 metres and approximately 5 metres of depth. Mark at Sphinx bergschrund When we exited onto the summit plateau there was quite a bit of fresh stuff, particularly on the corrie rim. You can see a full suite of pictures here. All-in-all, the prospect of these two patches surviving is very high.

It is exceptionally unusual to have deep snow in early September. One notable exception to this was 1976, when a storm during the first week of the month deposited large amounts on the Cairngorms. That said, snow in September is not unusual, albeit it is usually ephemeral.

I'm no meteorological expert, but I'd be surprised if this had any bearing on the matter. August falls, like most falls of snow, seem arbitrary and unpredictable. For sure, the falls of 2010 and 2011 (which was exceptional) were remarkable for their consistency (both on the 28th August). The fall yesterday was very slight and ephemeral by comparison. However, to link these events to sea temperature is beyond the scope of my expertise I'm afraid.

Don't forget ground temperature, stewfox. The ground temperature in August will be warmer than July, and snow falling on cooler ground will be more likely to stick. This is perhaps a reason why snow looks more visible in July, as it will tend to accumulate more readily.

Ah, but what is ‘early’? When does old season end and new season begin?! A contentious issue, and one I have pondered long and hard. My theory goes like this… The mid-way point between the summer solstice and the equinox is the 6th August (based on 92 days between the 21st June and 21st September). It seems to me that it would be sensible to have a date where the 'old' season ends and the 'new' one starts. The longest run of dates in July and August without snow ever being known is 7-13th August and 21-27th August. It seems to me, therefore, that any snow before the 7th August could be classified as old season, and any that falls after the 13th is 'new'. This is entirely arbitrary, though, and has no basis in science. However, it is neat and tidy!

Confirmation received today that snow was falling down to 3600 feet on Cairn Gorm. Light flurries, but snow nonetheless. Winter's on the way!

Currently minus 0.9degC on top of Cairn Gorm, with a very cold NW wind gusting to 50mph. However, as yet no reports of fresh snow. The radar suggests that the showers falling are farther east. The question is: will we get a third year of August snow!

Can you get your mate to email me and to confirm the particulars? This is very interesting, and would be excellent to have it confirmed? iainjamescameron@hotmail.comThanks!

1,245 and 1,343 metres respectively! Or, if you prefer old money, 4,084 and 4,406 feet. The mean temperature on top of Ben Nevis was measured at a fraction below freezing during the years of the observatory. A tad warmer nowadays, so probably in the region of 1degC. However, the Cairngorms are more likely to see early snow because of their position relative to the cold northerly weather systems that can rattle in from the Arctic in September. 2010 and 2011 witnessed snow on Ben Macdui on August 28th. It would be very unusual to have a run of 3 Augusts where snow fell, but MWIS is still stating that snow could fall on the afternoon/evening of the 30th. During a run of 69 years Adam Watson has seen fresh snow lying on the Cairngorms in 12 Julys, and in 69 years (excluding the current August) he has noted it in 10 years, with 4 August days the most in any one year (2011). August is undoubtedly the least snowy for fresh snow lying, and the middle part of the month the least of all. August snowfalls have been fairly light, but some in early July have been heavy with much drifting, as in 1948 and especially 1978. June is the third least snowy month, and September the fourth least.

Realistically, around 0 degrees. I'm no expert on this sort of thing, but 850hpa equates to around 5000 ft or so?

MWIS has just mentioned snow for the first time in a couple of months... Thursday, 30th August, 2012 Risk showery rain, mainly north Showers, mainly afternoon, but over the Cairngorms there may be intermittent rain for a few hours. Later snow on highest summits.

That's true but if you look at 2011 you will see the snow is virtually identical: ...and! 2010 substantially worse:

No problem. Observatory Gully was last snow-free in October 2006. It has held snow every since, albeit not in the same place. It almost vanished last year and the year before, but just hung in by the skin of its teeth!

Monday the 20th August saw a Scotland-wide survey of all remaining snow patches. A small army of volunteers was mobilised to cover ground stretching north to south and east to west. Numbers of patches in the last few years have hovered around the mid 30s during the August survey. As we suspected, though, the SW, W & NW direction of snowfalls that fell during the winter of 2011-2012 (coupled with the frequent freeze/thaw cycles) meant that the traditional (i.e. east facing) long-lying snow locations did rather well. So, what mountains carried snow? Nevis range - 32 (19 Ben Nevis, 10 Aonach Beag, 3 Aonach Mor) patches Beinn Bhrotain - 4 patches Sgurr nan Clachan Geala - 4 patches Tom a' Choinich - 1 patch Toll Creagach - 1 patch Beinn Dearg - 1 patch Macdui/Cairn Gorm - 19 patches Braeriach - 8 (7 in Garbh Choire Mor, one in Coire Bhrochain) Geal-charn - 1 patch Total - 71 patches The snow ranged from tiny patches to very large wreaths. The largest of which measured 98 metres (Garbh Choire Mor, Braeriach, below): The deepest snow to be found by us on Monday was that at Ben Nevis's Observatory Gully. It is somewhere in the order of 8 metres deep. This snow, however, sits on rocks and not soil. This means it is prone to being melted both from above and below. What this means in practise is that it will almost certainly melt before the snows of Garbh Choire Mor, which sit on soil. Anyway, the picture below shows the depth present on Ben Nevis. It isn't a glacier, though it resembles one! The prognosis for the snow this year is looking reasonable. The amount of warm weather is pretty normal for the time of year, and normal service now seems to have been resumed (unsettled in the north). If this pattern continues for the rest of the summer and early autumn then I think we could see a reasonable amount of survivals in the usual places (he says, tempting fate)!

It's still early, but I'd be very surprised if we didn't get at least a few survivals this year. Garbh Choire Mor looks healthier than at any time since 2008. I'll have a better idea after the survey on the 20th.In 1994 lasting snow didn't arrive until December! Some patches were still melting in November in mild weather. The moral of the story is that it's impossible to predict when snow is finally 'safe' this far in advance.

You can generally always find snow in Scotland if you know where to look. Even in very hot summers the snow doesn't always melt (a la 1976).

Which hill?! Snow will certainly persist into September on at least 3 of these hills, and possibly (probably) more.

Another update for all you chionophiles out there... August is now well and truly upon us. Snow is confined to some of the very highest nooks and crannies of the Scottish hills. In fact, you can almost count on two hands the mountains that have snow on them still. Most of these are in the Cairngorms and Nevis range, but there are a few 'regulars' which cling to their snow, even though they are unlikely to still show it after the end of this month. Hills where snow is still present (at time of writing): Nevis range 1. Ben Nevis 2. Aonach Mor 3. Aonach Beag Cairngorms 1. Beinn Bhrotain 2. Beinn a' Bhuird 3. Ben Avon 4. Braeriach 5. Ben Macdui 6. Cairn Gorm Others (maps are rough locations of where the snow is) 1. Sgurr nan Clachan Geala 2. An Riabhachan 3. Tom a' Choinich 4. Geal-charn The observant amongst you will notice that most of these patches face east, showing the prevelance of snow from the west this winter. This is crucial if snow is to persist through summer. East facing snows are more sheltered from the summer sun (beneath tall cliffs, as they tend to be) and less likely to be hammered by SW 'hairdryers' during the warmest months. Oh, congratulations are due to Helen Renni (h11lly), who has notched up her 34th consecutive month of skiing in the Cairngorms. She ventured up to Ciste Mhearad last Friday (3rd) to ski on some pretty deep snow. My favourite picture from that day is shown here. Glacier like! The snows on Ben Nevis and Garbh Choire Mor (Braeriach) are still extensive, the latter especially. Some good photographs of the snow can be seen in this trip report from the 31st July. I am again organising a Scotland-wide survey of all remaining snow on the 19th and 20th August, covering the mountains listed above. I shall post the results on here. If anyone is in the hills of Scotland that weekend then do make yourself known to me!

Though summer has arrived in parts of England, the high hills of Scotland remain cool (currently 4.8 degC on top of Cairn Gorm). Now that August is almost upon us, we're getting down to brass tacks in terms of snow patches. Most of the ones that remain are small, except the usual 'biggies' on Ben Nevis and the Cairngorms. The biggest surprise for me recently was to discover that, as of the 21st July, a small patch of snow persisted on An Stuc, a hill in the Ben Lawers region. This patch was already small on the 25th June (see here), but persisted until almost a month later (see here). It just goes to show that snow which is 'dug in' in a hollow can prove very resilient to melting. Of course, cool weather helps, but patches I've seen that I hadn't given much hope for have endured way beyond what I'd have thought. Another example of this was found at Glencoe ski area (on Meall a' Bhuiridh). On the 12th July, only two tiny patches remained on that hill (here). Remarkably, a tiny vestige remained until the 22nd, fully 10 days of summer weather without succumbing completely. There are other areas where snow persists as I write, and I'm conducting a Scotland-wide survey on the 19th and 20th of August. If anyone is planning a jaunt to the Highlands on these dates then please let me know, as I may ask them to keep an eye out on specific locations! Garbh Choire Mor, 21st July. Britain's snowiest place.

The first rule of reading anything in the news is that you must remember that it will almost certainly be exaggerated or mis-reported. This is because people who are doing the reporting will be non-specialist and don't really understand what it is they're reporting. Take for example the Guardian's 'story' on disappearing snow caps on Scotland and England's mountains, which uses as its reference the book that I co-authored (Cool Brittania). Almost all of what is written is taken out of context, and some of the bits he's written off his own back are just plane lies or misunderstandings of what we wrote. Unfortunately this sort of nonsense is peddled as fact ("it's in the paper, it must be true!") and Joe Public take them at their word.

The photograph shows a piece of ground that, before 1959, was last exposed in 1933 (i.e. the last time the snow melted). So in essence the snow-patch that was present in 1959 contained all the muck, dirt and general detritus that being 26 years old entails. As the snow melted, it deposited all this detritus on the rocks and ground it was lying on, giving the impression of having been given lick of black paint. Sandy Tewnion, the photographer, commented that the black residue was like tar. Not sure why that was, as I'm no expert.The most likely explanation is that it's nothing more than good old fashioned dirt!

*EDIT* - Just to illustrate the point, below is a photograph from 9th September 1959 of the ground under the Sphinx snow-patch, Braeriach. This piece of ground, exposed to daylight for probably only a handful of months since the 1700s, has nothing growing whatsoever below it.