23 Jun 2016

Thunderstorms: round two later today

Last night, severe thunderstorms swept up across south east England and East Anglia from northern France, giving frequent lightning and intense downpours of rain.

The heavy rain caused numerous flooding problems on the road and rail networks, with lots of delays and cancellations causing commuter chaos.

And, with another round of thunderstorms expected later today in similar areas, there is a risk of further disruption for the evening commute.

Lightning storm over the city of London with Tower Bridge in the foreground

What caused the thunderstorms?

Through yesterday, very moist, humid air drifted across southern and eastern parts of England from France, juicing the air with lots of potential energy.

This energy was then released by something called an upper trough high up in the atmosphere, which caused the air to become unstable and form thunderstorms.

What was particularly impressive about last night’s outbreak was that the thunderstorms were widespread and long-lasting, meaning that many places experienced them.

Here in the UK, thunderstorms are often hit and miss, with some places being hit and other places nearby missing them altogether.

Thousands of lightning strikes

Information from the lightningmaps.org website shows that across the UK, northern France and the Low Countries, there were around 160,000 lightning strikes between 6pm last night and midday today.

The map below shows each lightning strike plotted as a cross and you can clearly see the general south west to north east movement that the storms took.


In the UK, the storms were concentrated through Hampshire, Sussex, Kent, Essex, London and Suffolk, with a few reaching a little further north than this.

More thunderstorms later today

After a respite during this morning and early afternoon, further thunderstorms are expected towards Thursday evening and overnight into Friday.

The Met Office has issued a yellow “be aware” warning for East Anglia and south east England, as well as an amber “be prepared” warning for London.


London’s dense urban infrastructure, with lots of people and man-made surfaces, makes it more prone to flooding and disruption than the surrounding areas, which is why a higher level of warning has been issued.

Further heavy rain and frequent lightning could potentially cause more disruption, although pinpointing precisely which places will be worst hit is difficult when forecasting thunderstorms.

In the coming days, the risk of showers and thunderstorms transfers to northern and western parts of the UK, although they are unlikely to be as severe as what was experience last night.

Don’t forget, you can get the latest forecast on the Channel 4 Weather website. I’ll also be posting updates on Twitter – @liamdutton

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