BBC Weather meteorologist Tomasz Schafernaker warned there are “dark clouds on the horizon” and urged Britons to “take a brolly” on Friday as rain continues to halt the British heatwave.
The BBC forecaster said: “In the last few days we really have seen some dramatic shifts in the weather pattern from the heatwave in the south to much cooler weather.
“I think for many of us it really is a picture of sunshine and showers over the coming days.
“Actually, the Atlantic is looking a lot more active right now.
“We’ve even got a tropical storm out there in the Atlantic. Weather systems brewing in the northern portion of the ocean.”
Mr Schafernaker also referenced a dip in the jet stream over the UK. He said: “That means that we are seeing colder air dipping from the poles. So that’s what is over us right now.
“Whereas the heat that we had has now transferred away to the east of us.”
But the BBC Weather forecaster said it is “still going to feel warm” with the August sun remaining “very powerful”.
Over the weekend an area of low pressure will roll in off the Atlantic, which could trigger 70mph winds in parts of the UK.
The BBC forecaster said: “You see weather fronts there as well – that does mean rain. But not all the time and not absolutely everywhere.”
The Met Office warned that cyclonic weather systems will sweep in from the Atlantic over the next week giving the weather a shake up.
Met Office spokesman Richard Miles said: “It is going to cool down across the country over the next few days while turning much more changeable.
“Thursday will bring a risk of thunderstorms in the north and west and on Friday, although there will be sunny spells, there will be further showers with some thunder and hail.
“These showers will be quite heavy, widespread and frequent moving in from the west before spreading eastwards across the country.
“On Saturday, although it will be mainly dry and sunny in the southeast, there will be rain spreading across the country with a risk of gales along the western coasts; this is being driven by low-pressure coming in from the Atlantic.
“From Sunday it is turning wetter, cooler and windier generally and this is the picture for the following week with further areas of low pressure coming into the country, we do not see an immediate return of the very hot weather.”