Thunderbolts and lightning

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WHEN warm air meets cold air, as often happens in June and July, this can trigger thunderstorms.

People used to think that a particularly violent storm meant a famous person had died.

It could be their heroic nature, or the depth of their wickedness, that caused the disturbance as they passed out of this world.

Many people remembered the sudden death of Oliver Cromwell in 1658. A great gale had occurred a few days earlier, but the two events were soon connected.

Before long it was being said that a storm had marked the very night of the bogeyman’s death.

From the 15th to the 17th century it was common practice for church bells to be rung to make a storm go away, as the sound frightened away the demons of the air.

Despite the obvious dangers of lightning, especially to the bell ringers in a steeple, people seem to have been more concerned about the effects of thunder.

They believed it would make their beer and milk go sour.

To guard against thunderbolts, certain trees were planted near homes. Holly was effective against all evil influences, particularly lightning.

Some swore by laurel, while others championed elder as lightning-proof.

For the same reason, the fleshy rosettes of the houseleek plant were a familiar sight on roofs from the 1500s up to the 1960s.

A verse reminded people of which trees to avoid in a storm: “Beware of an oak; it draws the stroke. Avoid an ash; it courts the flash. Creep under the thorn, it can save you from harm.”

Bolts from the blue

While a good storm does freshen the air, displays of lightning are not to everyone’s taste.

Yet the chances of being hit by lightning today are slim, especially when most of us spend so much time indoors.

Amazingly, people can survive a direct strike. Lightning can pass over our bodies, thanks to the insulating properties of the skin.

But if anything containing metal is in contact with the skin, such as jewellery, a mobile, or earplugs, this flashover is interrupted.

So what to do if you’re caught out in the open? Keep away from stretches of water, because a bolt can flash sideways across a lake.

As lightning seeks the highest point to strike, resist the temptation to shelter under a tall tree.

On moors or hills the highest point might well be you, so make yourself as small as possible by crouching on the ground in a tight ball. The old advice to “creep under the thorn” was well founded.

Weather watching

The Met Office outlook for July is for more unsettled conditions. But if you’re wondering about the following day, the old lore can help.

First, go outside in the evening. High-flying midges and flies are a sign of fine weather and you’ll know if they’re up there, because swallows and swifts will be swooping around to catch them.

But if no swallows are to be seen, that means insects and birds are flying close to the ground and the next day will be wet or blustery.

Two helpful sayings are, “dew falling by night, the next day will be bright” and “summer mist at dawn, the day will be warm”.

Don’t forget that old favourite, “red sky at night, shepherds’ delight; red sky in the morning, sailors’ warning.” It’s well known because it’s reliable.

And whatever the conditions, you’ll see something beautiful. As John Ruskin wrote in 1879, “Never, if you can help it, miss seeing the sunset and the dawn.”

Victorian meteorologist Alexander Buchan identified a warm spell between July 12 and 15, but warm and dry don’t always go together. The 15th is St Swithin, the most notorious of prediction days; fingers crossed that it doesn’t rain then.