Video captures shelf cloud forming before huge thunderstorm hits south coast

The moment a huge shelf cloud forms has been captured on video, before thunder and lightning storms hit the south coast.

The amazing video and images show the cloud forming over Portland in Dorset.

Shelf clouds are harmless themselves but typically form at the leading edge of a thunderstorm.

Images also captured the huge lightning and thunderstorm which hit the region on Monday night.

Much of the region was hit by heavy downpours, thunder and lightning. It follows weeks of dry conditions, and extremely high temperatures - leading to a number of hosepipe bans.

But on Monday night thundery showers arrived with thousands of lightning strikes recorded across the region.

The drop in temperatures is in stark contrast to the weeks of warm weather most of the UK experienced throughout July and August.

But according to the Met Office more thundery showers are forecast for the rest of Tuesday and into the evening.

Frequent heavy showers are expected throughout the day and it will stay thundery through into this evening, with the risk of further storms.

Lightning strikes at Brighton Marina. Credit: Kris James

ITV Meridian's weather presenter Holly Green said: "This summer has been dominated by high pressure but low pressure took over - right on cue - as we ticked over into meteorological autumn.

"This has caused our atmosphere to become unstable - the air wants to rise - and this has led to intense showers and thunderstorms.

"This shelf or 'arcus' cloud is one of the best examples I've ever seen in this country. When cold air sinks beneath a cumulonimbus cloud it can run along the ground and displace warm, moist air.

"As this air rises and condenses it creates these impressive formations. If you see a shelf cloud it's a sure sign that thunder and lightning isn't far away.

Asked whether it's the end of the summery weather, Holly added: "We're certainly in an autumnal spell at the moment but further warm, sunny weather is definitely not out of the question.

"There's still plenty of time for an Indian summer!"