Britain can expect a ‘Spanish Plume’ of hot and humid air could bring temperatures of up to 30°C, according to forecasters.
London is most likely to see the hot weather, with temperatures reaching up to 30°C in the capital. Norwich and Cambridge may see temperatures of 28°C; while temperatures in Bath, Birmingham and Lincoln could rise to 25°C.
Strong winds from the stream are likely to encourage thunderstorms to develop with the Midlands and northern England most likely to be affected on Saturday.
The plume occurs when a large southwards dip in the high altitude jet stream develops to the west of Europe, pushing hot and humid air from Iberia into northern Europe and the British Isles.
Ewen McCallum, Met Office Chief Meteorologist, said: “‘Spanish Plume’ is actually a rather catchy name for a rather complex meteorological phenomenon which leads to warm conditions and heavy showers or thunderstorms over parts of the UK and north-west Europe.
“As the name suggests it is a plume of very warm air that pushes north from the Spanish plateau and reaches the British Isles on a southerly airflow.
“Of course over the UK we are normally affected by much cooler Atlantic air as cold fronts encroach from the west.
“Now when these two air masses meet, the very warm ‘plume’ air is forced to rise vigorously over the cooler Atlantic air and as a result produces thunderstorms.
“Because these features can cover large areas the storms are often grouped together and can give widespread, heavy rainfall, often accompanied by hail.”
It could also give a close and humid feel to the air, which could give it an uncomfortable feel, especially during the night. UK heatwave - 1st July is the hottest day for nine years
