Moonwalker - Adventures of a Midnight Mountaineer

MY heart goes out to the family and friends of Isobel Bytautas, who was killed by a lightning strike while walking in the Mamores.

Isobel was among a group of seven on Na Gruagaichean when she and another woman were hit. It must have been a horrific and terrifying ordeal for all involved.

The tragedy resonated with climbers and walkers everywhere. Like so many others, I was left feeling numb, unable to get this horror out of my mind. It seems beyond belief that a day's walking in the mountains could turn into such a nightmare. 

Lightning strikes are extremely rare, but that's little consolation when the consequences prove to be so devastating. Thunder and lightning storms awaken primal fears in us all. It's an evolutionary instinct to want to avoid a storm, to not be caught out in the open when they strike.

The highest risk of storms tends to be in the warmer, summer months when electrical pressure builds in the atmosphere, triggering torrential downpours. The full moon in July is often referred to as the Thunder Moon, due to the prevalence of thunderstorms.

There's usually some advance warning of approaching storms. You can see and hear one coming, sometimes even feel it; your skin can start to itch and your hair can stand on end. There may even be a hum and a spark from metal objects like ice axes.

The Mamores strike was associated with a thunderhead which had developed across Glen Creran then drifted over to Kinlochleven. It was a classic anvil-shaped storm cloud but it had not produced any lightning in the previous few hours. There had been no hint of thunder and lightning, some rain but nothing in the weather forecasts that would have caused undue concern. 

During a thunderstorm, the clouds become charged with electricity which arcs to earth accompanied by a flash of light. It tends to hit the nearest prominent features, such as trees, standing boulders or cairns. When it hits the ground, it spreads through the lines of least resistance like gullies or cracks in rock faces.

The first thing to do is lose height. Drop off summits or ridges, and try to find a flatter area. It may go against all instinct, especially when the rain is hammering down, but it is safer to sit down on a mat, ground sheet or even your rucksack. Pull your legs up to your chin and wrap your hands around your legs. Try to keep contact with the ground to a minimum – don't lean back on your hands.

Don't be tempted to seek shelter in gullies, caves or under trees, bridges or overhanging rocks. Do not stay inside a tent during a storm, as it could catch fire if hit.

You can often work out how far away lightning strikes are by using the 'flash-to-bang' method. This involves counting the number of seconds between the lightning and the crack of thunder that follows then dividing by five.

That will tell you have many miles you are from where the lightning just struck. Five seconds, for example, indicates the strike was one mile away, a ten-second gap means two miles away and so on.

During a recent descent from Beinn na Lap, we heard the rumbles and saw distant flashes. As we reached the final stretch before hitting the track, there was one flash which seemed to strike the ground just a few feet away from us and the sound followed almost immediately. I had never been so close to a strike. It was disconcerting, and I could swear I could have seen the ground smoulder briefly but maybe that was just the imagination running riot. 

It's a common misconception that walking poles or ice axes can act as lightning conductors. They don't and there is no need to discard them, but it may be prudent to lay them aside for peace of mind. It can be unnerving if they start sparking, and it's a brave soul who can stick to this rule. 

Coming off the lone Munro Geal Charn at Garva Bridge, we watched the sky turn black, the approaching storm racing towards us. It's an understatement to say it made us nervous with all the ironmongery, so we stashed our ice axes and poles under a bridge and came back to collect them later.

The chances of being hit by lightning may be ten million to one, but as the tragedy in the Mamores proved, there's never an absolute guarantee of safety. The best you can do is reduce the risk and hope the unthinkable never happens.