Freeheel,

As Chionophile pointed out to me in a personal email, you can see the rocks to the right of the snow have very little (none?) in the way of lichens on them, indicating long-lying snow. If you look around the perimeter of the existing snow (where it has been exposed for longer) you can see more of a green colour (i.e. mosses). Naturally, the closer to the snow the less there is. Some of these rocks, particularly the ones to the right of the snow and the left of the large boulder (I call it The Fallen Obelisk, and it’s visible in many of the pictures of this snow) in the centre of the picture, will not have been exposed since autumn 2006, so it’s hardly surprising they look as ‘clean’ as they do.

One of the reasons that some suspect this patch lasts so long is that the snow is ‘topped-up’ by avalanches during the winter. I don’t necessarily share your view that the snow is full of stones because of this. Certainly there are lots visible on the surface in this picture, but I think a lot of that can be put down to the fact that the smaller stones actually settle on the snow when they’ve fallen there over the course of the last few years, and as it melts this year to its lowest level in 3-years they obviously drop in level with it. As the snow melts, other small stones that are contained therein are exposed and join in the process. This gives the impression of the snow being littered with small stones, when in actual fact the snow has far more stones on the surface level than at any level within the snow. I hope that makes sense, as I’m probably not describing what I mean very well.

As for the Cairngorms snow, Dakishman was up at them at the weekend and he informed me he was going to put an account on here. Perhaps he’s been sidetracked! I’ll let him post the results of his trip, but the dimensions are broadly similar to when we visited on the 26th September, though some melting has occurred since then.

Thanks Firefly

Much appreciate your further commentary and yes, that was the photo I was having a closer look at. As you say the stones are smallish and I do follow your rational as to why they are distributed on the surface in this way. Fascinating stuff. Let us hope things have pretty much reached a nadir though and that this mild spell won't last for too much longer.

On that note, I wish you luck in finding a weather window on Saturday and maybe next week I'll try and have a further look at the patch on 'the ben' instead which might be more useful in terms of overall observation.

Thanks to the fabulous weekend efforts of Dakishman and Alan Halewood, we have a comprehensive record of all remaining Scottish snow, complete with photographs and measurements. We’ve already seen Alan’s contribution from Saturday of Aonach Beag, and now we can add Dakishman’s wonderful photographs and measurements to the mix.

Firstly, he went to Garbh Choire Mor on Saturday the 17th. Sphinx and Pinnacles were, in places, still holding on to the snow that fell in the first week in October. The patches have melted a bit since the 26th September, and there’s been a visible loss in depth, but there remains a good depth of snow in both patches, as can be seen below.



If you compare the photograph on the left (below) from Saturday to the one taken at more-or-less the same position of Pinnacles on the 26th September then you can compare them.



The total length/width of the total patches was 31m (20m length for Pinnacles and 10m width for Sphinx). A full set of pictures can be found here: [www.flickr.com]




Edited 2 times. Last edit at 20.20hrs Tue 20 Oct 09 by firefly.

Secondly, a slog up to Observatory Gully on Sunday 18th by the redoubtable Dakishman provided first-class pictures of the remaining snow there. The best of which (in my view), is the one below.


This picture shows the main snow-patch, which was 20m wide and 10m long top to bottom on the left hand side, and 8m long on the right. This main patch will have soon be split into three, with the thin, obvious bridge connecting the lower snow probably already broken as I type. The bridge connecting the deepest, heart-shaped patch with the one to its left will also soon disappear. On the positive side, the depth of the main patch (the dirtier, heart shaped patch) of 2.5m looks good, and substantial. The core of this patch is the snow that’s been around for a few years now, and will be very hard indeed.

The second section of snow, which sits to the right and slightly lower-down than the main patch is also a decent size (see below).


Lower, right hand patches with noticeable split in the upper section. Larger lower section approximately 15m x 7m x 1.2m, with upper section 4m x 2m x 0.6m

Also in the above picture you can see a smaller, shallower patch in the middle foreground, which was only 3m long x 1m wide.

As for Point 5 Gully… what a sorry sight that is!


Neither of the patches much more than 1m wide, and if not already gone then gone in the next few days.

Again, all pictures of the day’s trip are here: [www.flickr.com]

By my arithmetic, the total length of all snow on the 18th October (no material melting on the 17th due to cold, clear conditions) was 104m, worked out as follows:

1) Sphinx – 10m
2) Pinnacles – 20m
3) Aonach Beag – 25m
4) Observatory main patch – 20m
5) Observatory main patch lower – 5m
6) Observatory lower right patch 1 – 15m
7) Observatory lower right patch 2 – 4m
8) Observatory lower left patch – 3m
9) Point 5 Gully – 2m

An excellent weekend’s work, and a special pat on the back to Dakishman, whose efforts for the cause are humbling!




Edited 1 times. Last edit at 20.26hrs Tue 20 Oct 09 by firefly.

Andy

Ukweatherworld Manager
MBA Newsletter Editor



Edited 1 times. Last edit at 20.41hrs Tue 20 Oct 09 by Essan.

Okay, dunno what happened there .... anyway, picture of Aonach Beag taken from near Glen Roy in 17th October

[img.photobucket.com]

Andy

Ukweatherworld Manager
MBA Newsletter Editor

Agreed, Firefly, a grand effort by Dakishman. The fresh blown snow in early October helped reduce melting at Garbh Choire Mor, partly closing off air gaps at the back of the snow patches and the front of the Pinnacles patch. Also, the photos show that the surface hollows in the dirty greyish old snow are partly filled with whiter fresh snow, now already hardened by thawing and freezing.

About the Aonach Beag snow, Firefly correctly explained how the amount of stones on the surface gradually increases as a snow patch melts, even though no fresh stones fall on the surface. At Aonach Beag there will have been some stonefall during the summer, especially during heavy rainstorms, as well as during the main spring thaw, in addition to stones in avalanches. Firefly's explanation about the increasing amount of stones as a patch melts also applies to dirt on the surface, including ptarmigan dung, a frequent feature of the snow at Garbh Choire Mor.

Nobody knows for certain the relative importance of drifting versus avalanches in contributing to snow-patch depth,but most of the long-lying patches in Scotland are in sites backed by higher ground with a good fetch for collecting blown snow. At Aonach Beag there is certainly a big fetch at high altitude with S and SSW and SW winds, the prevailing winds in the Highlands during winter. There are also avalanches, but the relative importance has not been measured. I am inclined to think that blown snow is the more important factor at Aonach Beag and Ben Nevis and Garbh Choire Mor and the Aonach Mor site south of Easy Gully, whereas at the protalus patch on Aonach Mor the relative contribution of avalanches is likely to be higher.

As Firefly has stated, I wrote in an email to him that Alan Haywood's photo of the Aonach Beag snow showed many boulders without rock lichen or moss, clearly signifying prolonged snow lie. Further away from the snow is a band of boulders and bedrock carrying dark green moss. This occurs at all the long-lying Scottish snow patches. The mosses are snow specialists, which can withstand being under snow for most of the year, and occasionally for the whole year. Small bits of them can grow on boulders where the snow-lie is too long to allow rock lichens to grow, and the Aonach Beag site is an example of this, as are the snow patches for instance at Garbh Uisge Beag and Ciste Mhearad in the Cairngorms. An additional confounding issue in Lochaber at Aonach Beag and Aonach Mor and Ben Nevis is that the very heavy precipitation and associated large amounts of groundwater lead to high humidity and wet boulders and bedrocks, as compared with the drier climate further east as exemplified in Dakishman's photos of Garbh Choire Mor. At GCM, the bedrock behind the snow is too dry to support much growth of moss as compared with Aonach Beag.

Seumas Grannd at Inverdruie tells me that fresh snow lay on the Cairngorms down to about 3300-3400 feet on Monday morning, though disappearing later. I had expected it, because the temperature at Crathes was 42F at 0900 and light rain falling, so I judged that there would be snow above about 3000 feet. Later it turned milder, but the morning's snow will have been a wee top-up for the old snow patches in Garbh Choire Mor. The wind was light, so there would not have been much drifting.

Another interesting point about Dakishman's excellent photos is that the big heart-shaped patch at Observatory Gully shows fresh white snow along the top of the patch and well down it on the middle left. It completely covers the typical surface hollows in the old snow. These hollows are evident in the old snow along the bottom and on the right side of the patch. The hollows are usually one or two inches deep, so the photo indicates a substantial addition of new snow. This is not obvious in the bits further down, so probably it came from spindrift falling down the cliff behind, and lodging on the uppermost snow patch. I think I can see small pieces of new snow on the hollows in the old snow. This is certain in the photo of the patch below Sphinx Ridge in Garbh Choire Mor, which is a close-up shot, but the Observatory snow was further away. Dakishman may well have observed if there really was fresh snow in the hollows on the old snow at Observatory. I would expect it, given the amount of fresh snow covering the rest of the patch.

Nice one Attila, what a weekend
Like the pic ( Garbh Choire Mor 2 ) with the old dirty snow of Sphinx and Pinnacles surrouned by the clean fresh snow. See where the photo was taken was that your descent into the coire?
Was actually planning a trip there middle of next week.
Next time I get a free weekend I'll give you a shout.

RJ




Edited 1 times. Last edit at 23.50hrs Wed 21 Oct 09 by RJ.

Cheers folks! A pleasure! RJ - that photo was indeed from the descent - I think I took more or less the same route as yours back in August. If you get a chance to go out next week, go for it; the weather is still disappointingly mild so it will be good to see if there is any further change.

Against all the odds, Point 5 Gully snows are still holding firm, despite being tiny 4-days ago. Little difference between today (thanks to, who else, Alan Halewood) and Sunday, as can be seen from this photograph.

Also, The main Observatory patch has split into 2 (not yet 3!) parts, with the outlier to the right still a reasonable size.

The weather outlook for this week could hardly be worse for the remaining snow patches.An intense h.p. system over Europe going nowhere is blocking the southerly tracking lows from the Atlantic creating a potent stream of tropical maritime air with associated bands of rain/showers throughout the period,typically west is best for the usual hillfog,murk and drizzle!

The last few days have been mild enough but another week of this could be pivotal to this years final outcome,i certainly hope not.

Aonach Beag has to be the main concern though its aspect should at least afford it shelter from the S/S.W. winds.

This time last year it was about to snow at sea level..........




Edited 1 times. Last edit at 21.52hrs Sun 25 Oct 09 by coaster.

Remember 1994! Lasting snow arrived in December of that year, and snow was still melting through November in mild conditions.

I don’t know what the forecast is for the week, but this morning’s temperatures on Aonach Mor (around 1 Celcius) is encouraging, as is the temperature on Cairn Gorm (around 2 Celcius). Obviously this will fluctuate over the next few days, but temperatures in low to mid single figures shouldn’t be catastrophic for at least the larger of the patches. I’m sure the smaller Observatory Gully outliers will suffer, but the two large ones should be OK well into November. I think that Aonach Beag is more at risk, but I still think there was enough there to get a good way into November.

I’m planning a visit on the 31st to Aonach Beag, if anyone’s interested!

Yuk! 10°c overnight at 2300ft, torrential rain into the night, windy to boot. Can't have done the patches any favours, but it is at least dry with much lighter winds this morning in the East.

Never got any better during the day Alan.
Managed to get down into Garbh Choire Mor this afternoon, temp was definitely in double digits, rain pretty steady. Not a nice day at all especailly if your a snow patch. On the positive both sphinx (now roughly about 6m across) & pinnacles ( about 15m) are both solid and well dug in. More so pinnacles, but the weather over the next couple of weeks will be critical and probably require another visit in the near future or an observation from Macdui if someone is out on a fine day.

Unfortunately Iain wont be able to make this weekend. I expect that you might see a sizeable reduction from Alan Halewoods visit on the 17th.
Attila they were some footprints halfway up pinnacles are these yours or were they there when you were their? Very suprised as the snow is pretty solid ice.
Not many pics as it was too wet to have the camera out.



Edited 1 times. Last edit at 19.48hrs Wed 28 Oct 09 by RJ.

Attachments: sphinx (2).jpg (209kB)   pinnacles(1).jpg (213kB)   pinnacles (3).jpg (219kB)