Fogbow
- Simon
- 5 days ago
- 3 min read
It is a cloud stretched out in a perfect curve, it is a triumphal arch of mist, it is a white rainbow, it is a fogbow.
We are early and climbing up to the Grey Corries, east of Ben Nevis. Despite this hot summer, or perhaps because of it, the mountains are garlanded in morning mists.
Suddenly, a hanging cloud in the glen re-shapes. The centre rises, un-needed puffs disappear. Slanted light breaks through. It creates not the prism of colour you'd expect from sun and rain, but a shining portal of whiteness.
A portal to where? In a minute the cloudy remnant is gone, so there is no knowing, save for the fact that, for us, it opens the way to sun-scorched day on the tops.
The Oxford English Dictionary defines a fogbow as "a bow, similar to the rainbow, produced by the action of light on the particles of fog". It might arise from a sharp temperature change, like your breath in chilly air, or a fast-warming day after a cool summer night.
The droplets in fog and mist are tiny, much smaller than raindrops, and light acts on them in a different way. The colours of light mix together, rather than separating out into the seven rainbow tints. Instead, they show as white.
Fogbows must be rare or, surely, we would have seen one before, though perhaps not quite so rare in those places where more fogs develop. Here in the mountains, for instance.
Even after a succession of dry days in the Highlands, there is plenty of moisture and not just in the air. Enough for a thousand orchids...
And, in the lochan below Stob Ban...
Enough for tens of thousands of tadpoles...
Just to fill you in on the Grey Corries if you haven't been there, the main peaks are linked by a majestic zig-zag ridge. There are four Munros to be enjoyed, if you extend the walk by taking in the more independent pyramid of Stob Ban.
The rock of the ridge and the summits is ever-crumbling and shows as a white-ish grey as it cascades down the sides. From a distance it can look like dirty snow.
Blocks of the rock stand ready to fall and disintegrate. But where they are still whole, there is some easy scrambling.
After we left the car on a rough track south of Spean Bridge, the round trip to the Grey Corries took us nigh on 11 hours, with more than 2,000m of ascent.
We included two other walks on this trip. First was the climb to Aonach Mor and on to Aonach Beag (assisted by the gondola, for an easy day). Second, the spectacular loop taking in Càrn Mòr Dearg, the CMD Arête and Ben Nevis.
The Arête (you can see above) is a straightforward scramble, with an escape path to the side, and is a delight. After completing it, you might believe that all that separates you from the summit of Ben Nevis is a steep and windy path. It's not so simple, though. What comes next is a sizeable slope covered entirely with boulders, from bin-size to fridge-size, piled on top of each other. You have to try to find a line and pick your way higher.
The loop starts at the North Face car park. It took us seven and a half hours, with 1,700m of ascent. Even on a perfect day, it seemed to be very lightly travelled. Of course, the top of Ben Nevis can be crowded and the first half of the walk-off is with the descending throng. Then, though, you turn off past a lochan and you're on your own.
Thanks to Andy and David.
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