Why Summer Storms on August 15/16 - Lynmouth and Boscastle Flood Disasters

I have written the following article this week and it has appeared in newspapers like the Western Morning News today… But here I add some extra words and photographs…

There is always something ominous about a roll of thunder, but as I sit here on Exmoor listening to the drumming of heavy rain and the canon-retort of distant lightning, there is an extra edge to the foreboding. It comes not only because the Met Office has just issued an Amber Warning for severe thunderstorms - but also because it is exactly 70 years to the day since 34 people lost their lives during the Lynmouth Flood Disaster which occurred just a couple of dozen miles from where I am now.

Survivors of the Lynmouth Flood Disaster meeting on the 65th anniversary of the terrible event

Indeed, it is exactly 18 years to the day since extreme heavy rain caused the Boscastle Flood Disaster. 

What is it about this strange and ominous date?

On August 16, 1952 a rain-gauge on Exmoor showed that in the 20 hours before 9am, nine inches of rain fell across Exmoor’s Chains area causing the Lynmouth Flood Disaster. More than 90 million tons of water had cascaded down the steep narrow valleys of the twin rivers Lyn towards the small harbour village causing death and devastation beyond anything ever seen in the region during peacetime.

Special service at Lynmouth marking the 65th anniversary of the disaster

People forget that it wasn’t only Lynmouth which suffered such devastation that night. Of the 34 people who lost their lives, half a dozen perished in other parts of Exmoor National Park. 

So terrible was the rainfall - which fell in solid sheets rather than in single droplets -  babies, children, teenagers, back-packers, husbands and wives and the elderly were all lost as the normally innocent and picturesque streams of the moors built up massive walls of water. There was nowhere else for these walls of water to go but down the steep sided valleys - building and becoming more terrifying each time the spate was momentarily delayed by one of the area’s ancient stone packhorse bridges.  

Where the floodwaters once raged

I spent years as a journalist talking to survivors of the flood and well recall the late John Pedder of Lynmouth telling me how he’d made his way to safety across rooftops - watching as cars, buildings and whole trees swept by just feet away from him in a torrent which had turned the modest stream into a raging giant as wide as the Thames at Tower Bridge.

Eyewitnesses described clouds that accumulated over Exmoor as glowering a “purple black” - some even said the threatening skies had a weird greenish tinge. And more than one person observed that the clouds above North Devon and West Somerset were moving in completely opposite directions. 

The innocent looking River Lyn more than burst its banks in 1952

Within hours, one of the most violent precipitations this country has ever seen was underway. The bogs on top of Exmoor were quickly filled to overflowing and Lynmouth would soon be a disaster zone.

At the 65th commemoration of the terrible event I talked to a woman called Wendy Marker.  She was working at a local hotel on the evening of that fateful Friday night, when her parents decided to evacuate their home. 

“When I got back along the road I couldn't use the river path - they were all up at the school. Was I frightened? No, not really,” said Wendy. “I'd lived by the river all my life and was used to hearing it roar. The school was above where we lived and they were all there except three people who lived in one of the other cottages. They refused to leave. But then they were always a bit like that - the sort who'd peer out from behind their curtains at you. Very old.

“And I remember the great crash that happened at around one in the morning. That was that for the cottages - and for the three old people. All gone. Not a thing left.

“It”s strange really,” she added. “You know most people have got something handed down from their mum, or their grandmother. I haven't got a thing. Not a single hand-me-down. It all went in the flood.”

 The nine inches of rain which fell on the central plateau of Exmoor has only ever been equalled twice in the British Isles. Most of the precipitation fell between seven in the evening and midnight. More than 90 million tons of water cascaded down the steep narrow valleys of the twin rivers Lyn towards the small harbour village causing death and devastation beyond anything ever seen in the region during peacetime.

On the same night in August in 2004 a rain gauge in the Valency Valley recorded an awesome seven and a half inches of rain in just five hours - and that downpour built a wall of water that shot down the valley to cause the Boscastle Flood Disaster - in which, miraculous, not a single soul lost their lives.  

For months after the Boscastle Flood people found single shoes which had been washed out of the local shoe-shop

“And yet, just a few miles over the hill at Slaughterbridge, a rain-gauge linked to our centre here recorded just five inches during that time and another of our gauges, five miles distant again, was measuring almost nothing,” I was told by Martin Weiler, a regional strategic officer for the Environment Agency.

He showed me a high-speed replay of the incident on a radar screen. One thing soon became apparent – the eye of the storm lingered long and loud in just one spot on the computer map. It was stuck above the hills behind Boscastle.

Flood debris ion the Valency Valley above Boscastle

Radar shows storms in different colours – the more violent parts tend to be redder, moving up to mauve and eventually to pure white. You don’t get white blobs being recorded by radar over Britain often, but on this occasion a single white square was centred over the Valency River catchment area for the best part of two hours. 

Floodwaters smashed through roads above Boscastle

As I sit here on Exmoor on this August 16th I can’t help but wonder what the meteorologists are seeing now. They’ve already issued their Amber Weather Warning - like thousands of others in the region I will be praying the freak weather doesn’t strike for a third time on this fateful day. 

The rain did hit us last night. Really really heavy rain. The worst I’ve known in the 25 years I have lived in this cottage. I see on social media that the deluge caused floods and landslides all around this immediate area. I have just been for a walk around the valley and the results of the rain are plain to see. Long summer grass has been sort of combed downhill as if a hairbrush had stroked its way through the countryside. Rocks and stones and other debris lines most roads - especailly in palces

The footpath at my place washed down to bedrock by heavy rain