Around 29,000 lightning strikes light up sky across southern England

Around 29,000lightning strikes lit up the sky overnight, the Met Office has said,as thunderstorms caused flash flooding and travel disruption across parts of England.

The storms rolled into the south west on Monday evening and moved towards the south east during the night, with people reporting being woken up in the early hours by loud crashes of thunder and flashes of lightning.

London Fire Brigade said it responded to 400 calls overnight, including two house fires believed to be causedby lightning strikes, while a house in Bristol was set ablaze during a storm earlier in the evening.

It comes as England braces for temperatures of up to 40C, with the Met Office issuing a rare red alert set to come into force on Wednesday.

The Met Office confirmed that there were 29,000 flashes of lightning on Monday night and early on Tuesday morning in southern England.

That included lightning that went from cloud to cloud as well as the more "striking" cloud-to-ground fork lighting.

The number of lighting strikes is not particularly uncommon for storms developing after a hot and humid day, but the frequency and intensity of the lighting was spectacular.

While thunderstorms were forecast to track east across southern England last night, there is always going to be some uncertainty about the exact location of where - and how intense - they might be.

As well as lightning,very heavy rain in some areas lead to flash flooding.

The intense thunderstorms developed due to a couple of factors.

The first is that it was very warm if not hot across southern England on Monday afternoon and temperatures soared into the high 20s and low 30s.

This heat transfers into the atmosphere, giving it a lot of energy. That energy is then primed for a trigger to covert it into big cumulonimbus - thunder - clouds.

The trigger was an atmospheric disturbance higher in the atmosphere - which essentially allowed all that stored energy to be released, resulting in the intense thunderstorms.