The Met Office has issued a yellow weather warning for thunderstorms over parts of the UK, with the dramatic weather expected to begin within hours causing flooding, lightning and hail.
The weather warning was in place for a patch of England from Newcastle down to Manchester and northern parts of London.
The Met Office said there was a small chance that homes and businesses could be flooded quickly, with damage to some buildings from floodwater, lightning strikes, hail or strong winds.
Flooding and lightning strikes could cause delays and some cancellations to train and bus services while flooding could make driving conditions difficult.
There was also a small chance that power cuts could occur and service to some homes and businesses could be lost.
The unsettled weather is being caused by a low pressure system that is showing little signs of moving over the coming days.
It has been caught in the jet stream over the Atlantic and is bringing the wind and rain, while also driving up the warm air from southern Europe.
So with the low pressure likely to remain during next week it means that there will be plenty of rain which will probably be heaviest in the west.
BBC weather forecaster Ben Rich said earlier on Thursday that it was a "soggy start" to the day for many but most areas would see milder temperatures than in days past.
"Some of the heaviest rain through the morning will be down in the south east of England, up into East Anglia, the east Midland and then into Lincolnshire and parts of Yorkshire but some of that rain likely to get as far west as east Wales and parts of the West Country," he said.
"This lump though of really heavy rain will be making its way northwards throughout the day, essentially hugging this north east coast and so running into north east England and south east Scotland."
It was expected to be slightly milder on Thursday and with milder winds.
Mr Rich continued: "All the while things brightening up for Northern Ireland a much drier day to come here. Some sunny spells developing for Wales and the south and the south west of England.
"Not as windy as it was on Wednesday and still quite warm with temperatures through south Wales, south west England and the Channel islands could get get close to 20C but in the evening this lump of very heavy rain journeys northwards across Scotland, it may tend to ease a little as the night wears on."
But then this “relentless” low pressure system will see stronger winds on Friday with gusts reaching 50mph on exposed coasts, while there could also be thunder and lightning. Warmer air will also be driven across the UK with temperatures reaching 21C.
